1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/stat.h>
18 #include <sys/limits.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 
22 #include <dirent.h>
23 #include <stddef.h>
24 #include <string.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <fcntl.h>
28 #include <errno.h>
29 #include <unistd.h>
30 #include <sha1.h>
31 #include <zlib.h>
32 #include <fnmatch.h>
33 #include <libgen.h>
34 #include <uuid.h>
35 #include <util.h>
36 
37 #include "got_error.h"
38 #include "got_repository.h"
39 #include "got_reference.h"
40 #include "got_object.h"
41 #include "got_path.h"
42 #include "got_worktree.h"
43 #include "got_opentemp.h"
44 #include "got_diff.h"
45 
46 #include "got_lib_worktree.h"
47 #include "got_lib_sha1.h"
48 #include "got_lib_fileindex.h"
49 #include "got_lib_inflate.h"
50 #include "got_lib_delta.h"
51 #include "got_lib_object.h"
52 #include "got_lib_object_parse.h"
53 #include "got_lib_object_create.h"
54 #include "got_lib_object_idset.h"
55 #include "got_lib_diff.h"
56 
57 #ifndef MIN
58 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
59 #endif
60 
61 static const struct got_error *
62 create_meta_file(const char *path_got, const char *name, const char *content)
63 {
64 	const struct got_error *err = NULL;
65 	char *path;
66 
67 	if (asprintf(&path, "%s/%s", path_got, name) == -1)
68 		return got_error_from_errno("asprintf");
69 
70 	err = got_path_create_file(path, content);
71 	free(path);
72 	return err;
73 }
74 
75 static const struct got_error *
76 update_meta_file(const char *path_got, const char *name, const char *content)
77 {
78 	const struct got_error *err = NULL;
79 	FILE *tmpfile = NULL;
80 	char *tmppath = NULL;
81 	char *path = NULL;
82 
83 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
84 		err = got_error_from_errno("asprintf");
85 		path = NULL;
86 		goto done;
87 	}
88 
89 	err = got_opentemp_named(&tmppath, &tmpfile, path);
90 	if (err)
91 		goto done;
92 
93 	if (content) {
94 		int len = fprintf(tmpfile, "%s\n", content);
95 		if (len != strlen(content) + 1) {
96 			err = got_error_from_errno2("fprintf", tmppath);
97 			goto done;
98 		}
99 	}
100 
101 	if (rename(tmppath, path) != 0) {
102 		err = got_error_from_errno3("rename", tmppath, path);
103 		unlink(tmppath);
104 		goto done;
105 	}
106 
107 done:
108 	if (fclose(tmpfile) != 0 && err == NULL)
109 		err = got_error_from_errno2("fclose", tmppath);
110 	free(tmppath);
111 	return err;
112 }
113 
114 static const struct got_error *
115 read_meta_file(char **content, const char *path_got, const char *name)
116 {
117 	const struct got_error *err = NULL;
118 	char *path;
119 	int fd = -1;
120 	ssize_t n;
121 	struct stat sb;
122 
123 	*content = NULL;
124 
125 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
126 		err = got_error_from_errno("asprintf");
127 		path = NULL;
128 		goto done;
129 	}
130 
131 	fd = open(path, O_RDONLY | O_NOFOLLOW);
132 	if (fd == -1) {
133 		if (errno == ENOENT)
134 			err = got_error(GOT_ERR_WORKTREE_META);
135 		else
136 			err = got_error_from_errno2("open", path);
137 		goto done;
138 	}
139 	if (flock(fd, LOCK_SH | LOCK_NB) == -1) {
140 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
141 		    : got_error_from_errno2("flock", path));
142 		goto done;
143 	}
144 
145 	if (lstat(path, &sb) != 0) {
146 		err = got_error_from_errno2("lstat", path);
147 		goto done;
148 	}
149 	*content = calloc(1, sb.st_size);
150 	if (*content == NULL) {
151 		err = got_error_from_errno("calloc");
152 		goto done;
153 	}
154 
155 	n = read(fd, *content, sb.st_size);
156 	if (n != sb.st_size) {
157 		err = (n == -1 ? got_error_from_errno2("read", path) :
158 		    got_error(GOT_ERR_WORKTREE_META));
159 		goto done;
160 	}
161 	if ((*content)[sb.st_size - 1] != '\n') {
162 		err = got_error(GOT_ERR_WORKTREE_META);
163 		goto done;
164 	}
165 	(*content)[sb.st_size - 1] = '\0';
166 
167 done:
168 	if (fd != -1 && close(fd) == -1 && err == NULL)
169 		err = got_error_from_errno2("close", path_got);
170 	free(path);
171 	if (err) {
172 		free(*content);
173 		*content = NULL;
174 	}
175 	return err;
176 }
177 
178 static const struct got_error *
179 write_head_ref(const char *path_got, struct got_reference *head_ref)
180 {
181 	const struct got_error *err = NULL;
182 	char *refstr = NULL;
183 
184 	if (got_ref_is_symbolic(head_ref)) {
185 		refstr = got_ref_to_str(head_ref);
186 		if (refstr == NULL)
187 			return got_error_from_errno("got_ref_to_str");
188 	} else {
189 		refstr = strdup(got_ref_get_name(head_ref));
190 		if (refstr == NULL)
191 			return got_error_from_errno("strdup");
192 	}
193 	err = update_meta_file(path_got, GOT_WORKTREE_HEAD_REF, refstr);
194 	free(refstr);
195 	return err;
196 }
197 
198 const struct got_error *
199 got_worktree_init(const char *path, struct got_reference *head_ref,
200     const char *prefix, struct got_repository *repo)
201 {
202 	const struct got_error *err = NULL;
203 	struct got_object_id *commit_id = NULL;
204 	uuid_t uuid;
205 	uint32_t uuid_status;
206 	int obj_type;
207 	char *path_got = NULL;
208 	char *formatstr = NULL;
209 	char *absprefix = NULL;
210 	char *basestr = NULL;
211 	char *uuidstr = NULL;
212 
213 	if (strcmp(path, got_repo_get_path(repo)) == 0) {
214 		err = got_error(GOT_ERR_WORKTREE_REPO);
215 		goto done;
216 	}
217 
218 	err = got_ref_resolve(&commit_id, repo, head_ref);
219 	if (err)
220 		return err;
221 	err = got_object_get_type(&obj_type, repo, commit_id);
222 	if (err)
223 		return err;
224 	if (obj_type != GOT_OBJ_TYPE_COMMIT)
225 		return got_error(GOT_ERR_OBJ_TYPE);
226 
227 	if (!got_path_is_absolute(prefix)) {
228 		if (asprintf(&absprefix, "/%s", prefix) == -1)
229 			return got_error_from_errno("asprintf");
230 	}
231 
232 	/* Create top-level directory (may already exist). */
233 	if (mkdir(path, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
234 		err = got_error_from_errno2("mkdir", path);
235 		goto done;
236 	}
237 
238 	/* Create .got directory (may already exist). */
239 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
240 		err = got_error_from_errno("asprintf");
241 		goto done;
242 	}
243 	if (mkdir(path_got, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
244 		err = got_error_from_errno2("mkdir", path_got);
245 		goto done;
246 	}
247 
248 	/* Create an empty lock file. */
249 	err = create_meta_file(path_got, GOT_WORKTREE_LOCK, NULL);
250 	if (err)
251 		goto done;
252 
253 	/* Create an empty file index. */
254 	err = create_meta_file(path_got, GOT_WORKTREE_FILE_INDEX, NULL);
255 	if (err)
256 		goto done;
257 
258 	/* Write the HEAD reference. */
259 	err = write_head_ref(path_got, head_ref);
260 	if (err)
261 		goto done;
262 
263 	/* Record our base commit. */
264 	err = got_object_id_str(&basestr, commit_id);
265 	if (err)
266 		goto done;
267 	err = create_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, basestr);
268 	if (err)
269 		goto done;
270 
271 	/* Store path to repository. */
272 	err = create_meta_file(path_got, GOT_WORKTREE_REPOSITORY,
273 	    got_repo_get_path(repo));
274 	if (err)
275 		goto done;
276 
277 	/* Store in-repository path prefix. */
278 	err = create_meta_file(path_got, GOT_WORKTREE_PATH_PREFIX,
279 	    absprefix ? absprefix : prefix);
280 	if (err)
281 		goto done;
282 
283 	/* Generate UUID. */
284 	uuid_create(&uuid, &uuid_status);
285 	if (uuid_status != uuid_s_ok) {
286 		err = got_error_uuid(uuid_status);
287 		goto done;
288 	}
289 	uuid_to_string(&uuid, &uuidstr, &uuid_status);
290 	if (uuid_status != uuid_s_ok) {
291 		err = got_error_uuid(uuid_status);
292 		goto done;
293 	}
294 	err = create_meta_file(path_got, GOT_WORKTREE_UUID, uuidstr);
295 	if (err)
296 		goto done;
297 
298 	/* Stamp work tree with format file. */
299 	if (asprintf(&formatstr, "%d", GOT_WORKTREE_FORMAT_VERSION) == -1) {
300 		err = got_error_from_errno("asprintf");
301 		goto done;
302 	}
303 	err = create_meta_file(path_got, GOT_WORKTREE_FORMAT, formatstr);
304 	if (err)
305 		goto done;
306 
307 done:
308 	free(commit_id);
309 	free(path_got);
310 	free(formatstr);
311 	free(absprefix);
312 	free(basestr);
313 	free(uuidstr);
314 	return err;
315 }
316 
317 static const struct got_error *
318 open_worktree(struct got_worktree **worktree, const char *path)
319 {
320 	const struct got_error *err = NULL;
321 	char *path_got;
322 	char *formatstr = NULL;
323 	char *uuidstr = NULL;
324 	char *path_lock = NULL;
325 	char *base_commit_id_str = NULL;
326 	int version, fd = -1;
327 	const char *errstr;
328 	struct got_repository *repo = NULL;
329 	uint32_t uuid_status;
330 
331 	*worktree = NULL;
332 
333 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
334 		err = got_error_from_errno("asprintf");
335 		path_got = NULL;
336 		goto done;
337 	}
338 
339 	if (asprintf(&path_lock, "%s/%s", path_got, GOT_WORKTREE_LOCK) == -1) {
340 		err = got_error_from_errno("asprintf");
341 		path_lock = NULL;
342 		goto done;
343 	}
344 
345 	fd = open(path_lock, O_RDWR | O_EXLOCK | O_NONBLOCK);
346 	if (fd == -1) {
347 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
348 		    : got_error_from_errno2("open", path_lock));
349 		goto done;
350 	}
351 
352 	err = read_meta_file(&formatstr, path_got, GOT_WORKTREE_FORMAT);
353 	if (err)
354 		goto done;
355 
356 	version = strtonum(formatstr, 1, INT_MAX, &errstr);
357 	if (errstr) {
358 		err = got_error(GOT_ERR_WORKTREE_META);
359 		goto done;
360 	}
361 	if (version != GOT_WORKTREE_FORMAT_VERSION) {
362 		err = got_error(GOT_ERR_WORKTREE_VERS);
363 		goto done;
364 	}
365 
366 	*worktree = calloc(1, sizeof(**worktree));
367 	if (*worktree == NULL) {
368 		err = got_error_from_errno("calloc");
369 		goto done;
370 	}
371 	(*worktree)->lockfd = -1;
372 
373 	(*worktree)->root_path = strdup(path);
374 	if ((*worktree)->root_path == NULL) {
375 		err = got_error_from_errno("strdup");
376 		goto done;
377 	}
378 	err = read_meta_file(&(*worktree)->repo_path, path_got,
379 	    GOT_WORKTREE_REPOSITORY);
380 	if (err)
381 		goto done;
382 
383 	err = read_meta_file(&(*worktree)->path_prefix, path_got,
384 	    GOT_WORKTREE_PATH_PREFIX);
385 	if (err)
386 		goto done;
387 
388 	err = read_meta_file(&base_commit_id_str, path_got,
389 	    GOT_WORKTREE_BASE_COMMIT);
390 	if (err)
391 		goto done;
392 
393 	err = read_meta_file(&uuidstr, path_got, GOT_WORKTREE_UUID);
394 	if (err)
395 		goto done;
396 	uuid_from_string(uuidstr, &(*worktree)->uuid, &uuid_status);
397 	if (uuid_status != uuid_s_ok) {
398 		err = got_error_uuid(uuid_status);
399 		goto done;
400 	}
401 
402 	err = got_repo_open(&repo, (*worktree)->repo_path);
403 	if (err)
404 		goto done;
405 
406 	err = got_object_resolve_id_str(&(*worktree)->base_commit_id, repo,
407 	    base_commit_id_str);
408 	if (err)
409 		goto done;
410 
411 	err = read_meta_file(&(*worktree)->head_ref_name, path_got,
412 	    GOT_WORKTREE_HEAD_REF);
413 done:
414 	if (repo)
415 		got_repo_close(repo);
416 	free(path_got);
417 	free(path_lock);
418 	free(base_commit_id_str);
419 	free(uuidstr);
420 	free(formatstr);
421 	if (err) {
422 		if (fd != -1)
423 			close(fd);
424 		if (*worktree != NULL)
425 			got_worktree_close(*worktree);
426 		*worktree = NULL;
427 	} else
428 		(*worktree)->lockfd = fd;
429 
430 	return err;
431 }
432 
433 const struct got_error *
434 got_worktree_open(struct got_worktree **worktree, const char *path)
435 {
436 	const struct got_error *err = NULL;
437 
438 	do {
439 		err = open_worktree(worktree, path);
440 		if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT))
441 			return err;
442 		if (*worktree)
443 			return NULL;
444 		path = dirname(path);
445 		if (path == NULL)
446 			return got_error_from_errno2("dirname", path);
447 	} while (!((path[0] == '.' || path[0] == '/') && path[1] == '\0'));
448 
449 	return got_error(GOT_ERR_NOT_WORKTREE);
450 }
451 
452 const struct got_error *
453 got_worktree_close(struct got_worktree *worktree)
454 {
455 	const struct got_error *err = NULL;
456 	free(worktree->root_path);
457 	free(worktree->repo_path);
458 	free(worktree->path_prefix);
459 	free(worktree->base_commit_id);
460 	free(worktree->head_ref_name);
461 	if (worktree->lockfd != -1)
462 		if (close(worktree->lockfd) != 0)
463 			err = got_error_from_errno2("close",
464 			    got_worktree_get_root_path(worktree));
465 	free(worktree);
466 	return err;
467 }
468 
469 const char *
470 got_worktree_get_root_path(struct got_worktree *worktree)
471 {
472 	return worktree->root_path;
473 }
474 
475 const char *
476 got_worktree_get_repo_path(struct got_worktree *worktree)
477 {
478 	return worktree->repo_path;
479 }
480 
481 const char *
482 got_worktree_get_path_prefix(struct got_worktree *worktree)
483 {
484 	return worktree->path_prefix;
485 }
486 
487 const struct got_error *
488 got_worktree_match_path_prefix(int *match, struct got_worktree *worktree,
489     const char *path_prefix)
490 {
491 	char *absprefix = NULL;
492 
493 	if (!got_path_is_absolute(path_prefix)) {
494 		if (asprintf(&absprefix, "/%s", path_prefix) == -1)
495 			return got_error_from_errno("asprintf");
496 	}
497 	*match = (strcmp(absprefix ? absprefix : path_prefix,
498 	    worktree->path_prefix) == 0);
499 	free(absprefix);
500 	return NULL;
501 }
502 
503 const char *
504 got_worktree_get_head_ref_name(struct got_worktree *worktree)
505 {
506 	return worktree->head_ref_name;
507 }
508 
509 const struct got_error *
510 got_worktree_set_head_ref(struct got_worktree *worktree,
511     struct got_reference *head_ref)
512 {
513 	const struct got_error *err = NULL;
514 	char *path_got = NULL, *head_ref_name = NULL;
515 
516 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
517 	    GOT_WORKTREE_GOT_DIR) == -1) {
518 		err = got_error_from_errno("asprintf");
519 		path_got = NULL;
520 		goto done;
521 	}
522 
523 	head_ref_name = strdup(got_ref_get_name(head_ref));
524 	if (head_ref_name == NULL) {
525 		err = got_error_from_errno("strdup");
526 		goto done;
527 	}
528 
529 	err = write_head_ref(path_got, head_ref);
530 	if (err)
531 		goto done;
532 
533 	free(worktree->head_ref_name);
534 	worktree->head_ref_name = head_ref_name;
535 done:
536 	free(path_got);
537 	if (err)
538 		free(head_ref_name);
539 	return err;
540 }
541 
542 struct got_object_id *
543 got_worktree_get_base_commit_id(struct got_worktree *worktree)
544 {
545 	return worktree->base_commit_id;
546 }
547 
548 const struct got_error *
549 got_worktree_set_base_commit_id(struct got_worktree *worktree,
550     struct got_repository *repo, struct got_object_id *commit_id)
551 {
552 	const struct got_error *err;
553 	struct got_object *obj = NULL;
554 	char *id_str = NULL;
555 	char *path_got = NULL;
556 
557 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
558 	    GOT_WORKTREE_GOT_DIR) == -1) {
559 		err = got_error_from_errno("asprintf");
560 		path_got = NULL;
561 		goto done;
562 	}
563 
564 	err = got_object_open(&obj, repo, commit_id);
565 	if (err)
566 		return err;
567 
568 	if (obj->type != GOT_OBJ_TYPE_COMMIT) {
569 		err = got_error(GOT_ERR_OBJ_TYPE);
570 		goto done;
571 	}
572 
573 	/* Record our base commit. */
574 	err = got_object_id_str(&id_str, commit_id);
575 	if (err)
576 		goto done;
577 	err = update_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, id_str);
578 	if (err)
579 		goto done;
580 
581 	free(worktree->base_commit_id);
582 	worktree->base_commit_id = got_object_id_dup(commit_id);
583 	if (worktree->base_commit_id == NULL) {
584 		err = got_error_from_errno("got_object_id_dup");
585 		goto done;
586 	}
587 done:
588 	if (obj)
589 		got_object_close(obj);
590 	free(id_str);
591 	free(path_got);
592 	return err;
593 }
594 
595 static const struct got_error *
596 lock_worktree(struct got_worktree *worktree, int operation)
597 {
598 	if (flock(worktree->lockfd, operation | LOCK_NB) == -1)
599 		return (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
600 		    : got_error_from_errno2("flock",
601 		    got_worktree_get_root_path(worktree)));
602 	return NULL;
603 }
604 
605 static const struct got_error *
606 add_dir_on_disk(struct got_worktree *worktree, const char *path)
607 {
608 	const struct got_error *err = NULL;
609 	char *abspath;
610 
611 	if (asprintf(&abspath, "%s/%s", worktree->root_path, path) == -1)
612 		return got_error_from_errno("asprintf");
613 
614 	err = got_path_mkdir(abspath);
615 	if (err && err->code == GOT_ERR_ERRNO && errno == EEXIST) {
616 		struct stat sb;
617 		err = NULL;
618 		if (lstat(abspath, &sb) == -1) {
619 			err = got_error_from_errno2("lstat", abspath);
620 		} else if (!S_ISDIR(sb.st_mode)) {
621 			/* TODO directory is obstructed; do something */
622 			err = got_error(GOT_ERR_FILE_OBSTRUCTED);
623 		}
624 	}
625 	free(abspath);
626 	return err;
627 }
628 
629 static const struct got_error *
630 check_file_contents_equal(int *same, FILE *f1, FILE *f2)
631 {
632 	const struct got_error *err = NULL;
633 	uint8_t fbuf1[8192];
634 	uint8_t fbuf2[8192];
635 	size_t flen1 = 0, flen2 = 0;
636 
637 	*same = 1;
638 
639 	for (;;) {
640 		flen1 = fread(fbuf1, 1, sizeof(fbuf1), f1);
641 		if (flen1 == 0 && ferror(f1)) {
642 			err = got_error_from_errno("fread");
643 			break;
644 		}
645 		flen2 = fread(fbuf2, 1, sizeof(fbuf2), f2);
646 		if (flen2 == 0 && ferror(f2)) {
647 			err = got_error_from_errno("fread");
648 			break;
649 		}
650 		if (flen1 == 0) {
651 			if (flen2 != 0)
652 				*same = 0;
653 			break;
654 		} else if (flen2 == 0) {
655 			if (flen1 != 0)
656 				*same = 0;
657 			break;
658 		} else if (flen1 == flen2) {
659 			if (memcmp(fbuf1, fbuf2, flen2) != 0) {
660 				*same = 0;
661 				break;
662 			}
663 		} else {
664 			*same = 0;
665 			break;
666 		}
667 	}
668 
669 	return err;
670 }
671 
672 static const struct got_error *
673 check_files_equal(int *same, const char *f1_path, const char *f2_path)
674 {
675 	const struct got_error *err = NULL;
676 	struct stat sb;
677 	size_t size1, size2;
678 	FILE *f1 = NULL, *f2 = NULL;
679 
680 	*same = 1;
681 
682 	if (lstat(f1_path, &sb) != 0) {
683 		err = got_error_from_errno2("lstat", f1_path);
684 		goto done;
685 	}
686 	size1 = sb.st_size;
687 
688 	if (lstat(f2_path, &sb) != 0) {
689 		err = got_error_from_errno2("lstat", f2_path);
690 		goto done;
691 	}
692 	size2 = sb.st_size;
693 
694 	if (size1 != size2) {
695 		*same = 0;
696 		return NULL;
697 	}
698 
699 	f1 = fopen(f1_path, "r");
700 	if (f1 == NULL)
701 		return got_error_from_errno2("open", f1_path);
702 
703 	f2 = fopen(f2_path, "r");
704 	if (f2 == NULL) {
705 		err = got_error_from_errno2("open", f2_path);
706 		goto done;
707 	}
708 
709 	err = check_file_contents_equal(same, f1, f2);
710 done:
711 	if (f1 && fclose(f1) != 0 && err == NULL)
712 		err = got_error_from_errno("fclose");
713 	if (f2 && fclose(f2) != 0 && err == NULL)
714 		err = got_error_from_errno("fclose");
715 
716 	return err;
717 }
718 
719 /*
720  * Perform a 3-way merge where blob_orig acts as the common ancestor,
721  * blob_deriv acts as the first derived version, and the file on disk
722  * acts as the second derived version.
723  */
724 static const struct got_error *
725 merge_blob(int *local_changes_subsumed, struct got_worktree *worktree,
726     struct got_blob_object *blob_orig, const char *ondisk_path,
727     const char *path, uint16_t st_mode, struct got_blob_object *blob_deriv,
728     struct got_object_id *deriv_base_commit_id,
729     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
730     void *progress_arg)
731 {
732 	const struct got_error *err = NULL;
733 	int merged_fd = -1;
734 	FILE *f_deriv = NULL, *f_orig = NULL;
735 	char *blob_deriv_path = NULL, *blob_orig_path = NULL;
736 	char *merged_path = NULL, *base_path = NULL;
737 	char *id_str = NULL;
738 	char *label_deriv = NULL;
739 	int overlapcnt = 0;
740 	char *parent;
741 
742 	*local_changes_subsumed = 0;
743 
744 	parent = dirname(ondisk_path);
745 	if (parent == NULL)
746 		return got_error_from_errno2("dirname", ondisk_path);
747 
748 	if (asprintf(&base_path, "%s/got-merged", parent) == -1)
749 		return got_error_from_errno("asprintf");
750 
751 	err = got_opentemp_named_fd(&merged_path, &merged_fd, base_path);
752 	if (err)
753 		goto done;
754 
755 	free(base_path);
756 	if (asprintf(&base_path, "%s/got-merge-blob-deriv", parent) == -1) {
757 		err = got_error_from_errno("asprintf");
758 		base_path = NULL;
759 		goto done;
760 	}
761 
762 	err = got_opentemp_named(&blob_deriv_path, &f_deriv, base_path);
763 	if (err)
764 		goto done;
765 	err = got_object_blob_dump_to_file(NULL, NULL, NULL, f_deriv,
766 	    blob_deriv);
767 	if (err)
768 		goto done;
769 
770 	free(base_path);
771 	if (asprintf(&base_path, "%s/got-merge-blob-orig", parent) == -1) {
772 		err = got_error_from_errno("asprintf");
773 		base_path = NULL;
774 		goto done;
775 	}
776 
777 	err = got_opentemp_named(&blob_orig_path, &f_orig, base_path);
778 	if (err)
779 		goto done;
780 	if (blob_orig) {
781 		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f_orig,
782 		    blob_orig);
783 		if (err)
784 			goto done;
785 	} else {
786 		/*
787 		 * If the file has no blob, this is an "add vs add" conflict,
788 		 * and we simply use an empty ancestor file to make both files
789 		 * appear in the merged result in their entirety.
790 		 */
791 	}
792 
793 	err = got_object_id_str(&id_str, deriv_base_commit_id);
794 	if (err)
795 		goto done;
796 	if (asprintf(&label_deriv, "commit %s", id_str) == -1) {
797 		err = got_error_from_errno("asprintf");
798 		goto done;
799 	}
800 
801 	err = got_merge_diff3(&overlapcnt, merged_fd, blob_deriv_path,
802 	    blob_orig_path, ondisk_path, label_deriv, path);
803 	if (err)
804 		goto done;
805 
806 	err = (*progress_cb)(progress_arg,
807 	    overlapcnt > 0 ? GOT_STATUS_CONFLICT : GOT_STATUS_MERGE, path);
808 	if (err)
809 		goto done;
810 
811 	if (fsync(merged_fd) != 0) {
812 		err = got_error_from_errno("fsync");
813 		goto done;
814 	}
815 
816 	/* Check if a clean merge has subsumed all local changes. */
817 	if (overlapcnt == 0) {
818 		err = check_files_equal(local_changes_subsumed, blob_deriv_path,
819 		    merged_path);
820 		if (err)
821 			goto done;
822 	}
823 
824 	if (chmod(merged_path, st_mode) != 0) {
825 		err = got_error_from_errno2("chmod", merged_path);
826 		goto done;
827 	}
828 
829 	if (rename(merged_path, ondisk_path) != 0) {
830 		err = got_error_from_errno3("rename", merged_path,
831 		    ondisk_path);
832 		unlink(merged_path);
833 		goto done;
834 	}
835 
836 done:
837 	if (merged_fd != -1 && close(merged_fd) != 0 && err == NULL)
838 		err = got_error_from_errno("close");
839 	if (f_deriv && fclose(f_deriv) != 0 && err == NULL)
840 		err = got_error_from_errno("fclose");
841 	if (f_orig && fclose(f_orig) != 0 && err == NULL)
842 		err = got_error_from_errno("fclose");
843 	free(merged_path);
844 	free(base_path);
845 	if (blob_deriv_path) {
846 		unlink(blob_deriv_path);
847 		free(blob_deriv_path);
848 	}
849 	if (blob_orig_path) {
850 		unlink(blob_orig_path);
851 		free(blob_orig_path);
852 	}
853 	free(id_str);
854 	free(label_deriv);
855 	return err;
856 }
857 
858 static const struct got_error *
859 update_blob_fileindex_entry(struct got_worktree *worktree,
860     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
861     const char *ondisk_path, const char *path, struct got_blob_object *blob,
862     int update_timestamps)
863 {
864 	const struct got_error *err = NULL;
865 
866 	if (ie == NULL)
867 		ie = got_fileindex_entry_get(fileindex, path);
868 	if (ie)
869 		err = got_fileindex_entry_update(ie, ondisk_path,
870 		    blob->id.sha1, worktree->base_commit_id->sha1,
871 		    update_timestamps);
872 	else {
873 		struct got_fileindex_entry *new_ie;
874 		err = got_fileindex_entry_alloc(&new_ie, ondisk_path,
875 		    path, blob->id.sha1, worktree->base_commit_id->sha1);
876 		if (!err)
877 			err = got_fileindex_entry_add(fileindex, new_ie);
878 	}
879 	return err;
880 }
881 
882 static const struct got_error *
883 install_blob(struct got_worktree *worktree, const char *ondisk_path,
884    const char *path, uint16_t te_mode, uint16_t st_mode,
885    struct got_blob_object *blob, int restoring_missing_file,
886    int reverting_versioned_file, struct got_repository *repo,
887    got_worktree_checkout_cb progress_cb, void *progress_arg)
888 {
889 	const struct got_error *err = NULL;
890 	int fd = -1;
891 	size_t len, hdrlen;
892 	int update = 0;
893 	char *tmppath = NULL;
894 
895 	fd = open(ondisk_path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
896 	    GOT_DEFAULT_FILE_MODE);
897 	if (fd == -1) {
898 		if (errno == ENOENT) {
899 			char *parent = dirname(path);
900 			if (parent == NULL)
901 				return got_error_from_errno2("dirname", path);
902 			err = add_dir_on_disk(worktree, parent);
903 			if (err)
904 				return err;
905 			fd = open(ondisk_path,
906 			    O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
907 			    GOT_DEFAULT_FILE_MODE);
908 			if (fd == -1)
909 				return got_error_from_errno2("open",
910 				    ondisk_path);
911 		} else if (errno == EEXIST) {
912 			if (!S_ISREG(st_mode)) {
913 				/* TODO file is obstructed; do something */
914 				err = got_error(GOT_ERR_FILE_OBSTRUCTED);
915 				goto done;
916 			} else {
917 				err = got_opentemp_named_fd(&tmppath, &fd,
918 				    ondisk_path);
919 				if (err)
920 					goto done;
921 				update = 1;
922 			}
923 		} else
924 			return got_error_from_errno2("open", ondisk_path);
925 	}
926 
927 	if (restoring_missing_file)
928 		err = (*progress_cb)(progress_arg, GOT_STATUS_MISSING, path);
929 	else if (reverting_versioned_file)
930 		err = (*progress_cb)(progress_arg, GOT_STATUS_REVERT, path);
931 	else
932 		err = (*progress_cb)(progress_arg,
933 		    update ? GOT_STATUS_UPDATE : GOT_STATUS_ADD, path);
934 	if (err)
935 		goto done;
936 
937 	hdrlen = got_object_blob_get_hdrlen(blob);
938 	do {
939 		const uint8_t *buf = got_object_blob_get_read_buf(blob);
940 		err = got_object_blob_read_block(&len, blob);
941 		if (err)
942 			break;
943 		if (len > 0) {
944 			/* Skip blob object header first time around. */
945 			ssize_t outlen = write(fd, buf + hdrlen, len - hdrlen);
946 			if (outlen == -1) {
947 				err = got_error_from_errno("write");
948 				goto done;
949 			} else if (outlen != len - hdrlen) {
950 				err = got_error(GOT_ERR_IO);
951 				goto done;
952 			}
953 			hdrlen = 0;
954 		}
955 	} while (len != 0);
956 
957 	if (fsync(fd) != 0) {
958 		err = got_error_from_errno("fsync");
959 		goto done;
960 	}
961 
962 	if (update) {
963 		if (rename(tmppath, ondisk_path) != 0) {
964 			err = got_error_from_errno3("rename", tmppath,
965 			    ondisk_path);
966 			unlink(tmppath);
967 			goto done;
968 		}
969 	}
970 
971 	if (te_mode & S_IXUSR) {
972 		if (chmod(ondisk_path, st_mode | S_IXUSR) == -1) {
973 			err = got_error_from_errno2("chmod", ondisk_path);
974 			goto done;
975 		}
976 	} else {
977 		if (chmod(ondisk_path, st_mode & ~S_IXUSR) == -1) {
978 			err = got_error_from_errno2("chmod", ondisk_path);
979 			goto done;
980 		}
981 	}
982 
983 done:
984 	if (fd != -1 && close(fd) != 0 && err == NULL)
985 		err = got_error_from_errno("close");
986 	free(tmppath);
987 	return err;
988 }
989 
990 /* Upgrade STATUS_MODIFY to STATUS_CONFLICT if a conflict marker is found. */
991 static const struct got_error *
992 get_modified_file_content_status(unsigned char *status, FILE *f)
993 {
994 	const struct got_error *err = NULL;
995 	const char *markers[3] = {
996 		GOT_DIFF_CONFLICT_MARKER_BEGIN,
997 		GOT_DIFF_CONFLICT_MARKER_SEP,
998 		GOT_DIFF_CONFLICT_MARKER_END
999 	};
1000 	int i = 0;
1001 	char *line;
1002 	size_t len;
1003 	const char delim[3] = {'\0', '\0', '\0'};
1004 
1005 	while (*status == GOT_STATUS_MODIFY) {
1006 		line = fparseln(f, &len, NULL, delim, 0);
1007 		if (line == NULL) {
1008 			if (feof(f))
1009 				break;
1010 			err = got_ferror(f, GOT_ERR_IO);
1011 			break;
1012 		}
1013 
1014 		if (strncmp(line, markers[i], strlen(markers[i])) == 0) {
1015 			if (strcmp(markers[i], GOT_DIFF_CONFLICT_MARKER_END)
1016 			    == 0)
1017 				*status = GOT_STATUS_CONFLICT;
1018 			else
1019 				i++;
1020 		}
1021 	}
1022 
1023 	return err;
1024 }
1025 
1026 static int
1027 stat_info_differs(struct got_fileindex_entry *ie, struct stat *sb)
1028 {
1029 	return !(ie->ctime_sec == sb->st_ctime &&
1030 	    ie->ctime_nsec == sb->st_ctimensec &&
1031 	    ie->mtime_sec == sb->st_mtime &&
1032 	    ie->mtime_nsec == sb->st_mtimensec &&
1033 	    ie->size == (sb->st_size & 0xffffffff));
1034 }
1035 
1036 static const struct got_error *
1037 get_file_status(unsigned char *status, struct stat *sb,
1038     struct got_fileindex_entry *ie, const char *abspath,
1039     struct got_repository *repo)
1040 {
1041 	const struct got_error *err = NULL;
1042 	struct got_object_id id;
1043 	size_t hdrlen;
1044 	FILE *f = NULL;
1045 	uint8_t fbuf[8192];
1046 	struct got_blob_object *blob = NULL;
1047 	size_t flen, blen;
1048 
1049 	*status = GOT_STATUS_NO_CHANGE;
1050 
1051 	if (lstat(abspath, sb) == -1) {
1052 		if (errno == ENOENT) {
1053 			if (ie) {
1054 				if (got_fileindex_entry_has_file_on_disk(ie))
1055 					*status = GOT_STATUS_MISSING;
1056 				else
1057 					*status = GOT_STATUS_DELETE;
1058 				sb->st_mode =
1059 				    ((ie->mode >> GOT_FILEIDX_MODE_PERMS_SHIFT)
1060 				    & (S_IRWXU | S_IRWXG | S_IRWXO));
1061 			} else
1062 				sb->st_mode = GOT_DEFAULT_FILE_MODE;
1063 			return NULL;
1064 		}
1065 		return got_error_from_errno2("lstat", abspath);
1066 	}
1067 
1068 	if (!S_ISREG(sb->st_mode)) {
1069 		*status = GOT_STATUS_OBSTRUCTED;
1070 		return NULL;
1071 	}
1072 
1073 	if (ie == NULL)
1074 		return NULL;
1075 
1076 	if (!got_fileindex_entry_has_file_on_disk(ie)) {
1077 		*status = GOT_STATUS_DELETE;
1078 		return NULL;
1079 	} else if (!got_fileindex_entry_has_blob(ie)) {
1080 		*status = GOT_STATUS_ADD;
1081 		return NULL;
1082 	}
1083 
1084 	if (!stat_info_differs(ie, sb))
1085 		return NULL;
1086 
1087 	memcpy(id.sha1, ie->blob_sha1, sizeof(id.sha1));
1088 	err = got_object_open_as_blob(&blob, repo, &id, sizeof(fbuf));
1089 	if (err)
1090 		return err;
1091 
1092 	f = fopen(abspath, "r");
1093 	if (f == NULL) {
1094 		err = got_error_from_errno2("fopen", abspath);
1095 		goto done;
1096 	}
1097 	hdrlen = got_object_blob_get_hdrlen(blob);
1098 	for (;;) {
1099 		const uint8_t *bbuf = got_object_blob_get_read_buf(blob);
1100 		err = got_object_blob_read_block(&blen, blob);
1101 		if (err)
1102 			goto done;
1103 		/* Skip length of blob object header first time around. */
1104 		flen = fread(fbuf, 1, sizeof(fbuf) - hdrlen, f);
1105 		if (flen == 0 && ferror(f)) {
1106 			err = got_error_from_errno("fread");
1107 			goto done;
1108 		}
1109 		if (blen == 0) {
1110 			if (flen != 0)
1111 				*status = GOT_STATUS_MODIFY;
1112 			break;
1113 		} else if (flen == 0) {
1114 			if (blen != 0)
1115 				*status = GOT_STATUS_MODIFY;
1116 			break;
1117 		} else if (blen - hdrlen == flen) {
1118 			/* Skip blob object header first time around. */
1119 			if (memcmp(bbuf + hdrlen, fbuf, flen) != 0) {
1120 				*status = GOT_STATUS_MODIFY;
1121 				break;
1122 			}
1123 		} else {
1124 			*status = GOT_STATUS_MODIFY;
1125 			break;
1126 		}
1127 		hdrlen = 0;
1128 	}
1129 
1130 	if (*status == GOT_STATUS_MODIFY) {
1131 		rewind(f);
1132 		err = get_modified_file_content_status(status, f);
1133 	}
1134 done:
1135 	if (blob)
1136 		got_object_blob_close(blob);
1137 	if (f)
1138 		fclose(f);
1139 	return err;
1140 }
1141 
1142 /*
1143  * Update timestamps in the file index if a file is unmodified and
1144  * we had to run a full content comparison to find out.
1145  */
1146 static const struct got_error *
1147 sync_timestamps(char *ondisk_path, unsigned char status,
1148     struct got_fileindex_entry *ie, struct stat *sb)
1149 {
1150 	if (status == GOT_STATUS_NO_CHANGE && stat_info_differs(ie, sb))
1151 		return got_fileindex_entry_update(ie, ondisk_path,
1152 		    ie->blob_sha1, ie->commit_sha1, 1);
1153 
1154 	return NULL;
1155 }
1156 
1157 static const struct got_error *
1158 update_blob(struct got_worktree *worktree,
1159     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
1160     struct got_tree_entry *te, const char *path,
1161     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1162     void *progress_arg)
1163 {
1164 	const struct got_error *err = NULL;
1165 	struct got_blob_object *blob = NULL;
1166 	char *ondisk_path;
1167 	unsigned char status = GOT_STATUS_NO_CHANGE;
1168 	struct stat sb;
1169 
1170 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
1171 		return got_error_from_errno("asprintf");
1172 
1173 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1174 	if (err)
1175 		goto done;
1176 
1177 	if (status == GOT_STATUS_OBSTRUCTED) {
1178 		err = (*progress_cb)(progress_arg, status, path);
1179 		goto done;
1180 	}
1181 
1182 	if (ie && status != GOT_STATUS_MISSING) {
1183 		if (got_fileindex_entry_has_commit(ie) &&
1184 		    memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
1185 		    SHA1_DIGEST_LENGTH) == 0) {
1186 			err = sync_timestamps(ondisk_path, status, ie, &sb);
1187 			if (err)
1188 				goto done;
1189 			err = (*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
1190 			    path);
1191 			goto done;
1192 		}
1193 		if (got_fileindex_entry_has_blob(ie) &&
1194 		    memcmp(ie->blob_sha1, te->id->sha1,
1195 		    SHA1_DIGEST_LENGTH) == 0) {
1196 			err = sync_timestamps(ondisk_path, status, ie, &sb);
1197 			goto done;
1198 		}
1199 	}
1200 
1201 	err = got_object_open_as_blob(&blob, repo, te->id, 8192);
1202 	if (err)
1203 		goto done;
1204 
1205 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_ADD) {
1206 		int update_timestamps;
1207 		struct got_blob_object *blob2 = NULL;
1208 		if (got_fileindex_entry_has_blob(ie)) {
1209 			struct got_object_id id2;
1210 			memcpy(id2.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1211 			err = got_object_open_as_blob(&blob2, repo, &id2, 8192);
1212 			if (err)
1213 				goto done;
1214 		}
1215 		err = merge_blob(&update_timestamps, worktree, blob2,
1216 		    ondisk_path, path, sb.st_mode, blob,
1217 		    worktree->base_commit_id, repo,
1218 		    progress_cb, progress_arg);
1219 		if (blob2)
1220 			got_object_blob_close(blob2);
1221 		/*
1222 		 * Do not update timestamps of files with local changes.
1223 		 * Otherwise, a future status walk would treat them as
1224 		 * unmodified files again.
1225 		 */
1226 		err = got_fileindex_entry_update(ie, ondisk_path,
1227 		    blob->id.sha1, worktree->base_commit_id->sha1,
1228 		    update_timestamps);
1229 	} else if (status == GOT_STATUS_DELETE) {
1230 		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, path);
1231 		if (err)
1232 			goto done;
1233 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1234 		    ondisk_path, path, blob, 0);
1235 		if (err)
1236 			goto done;
1237 	} else {
1238 		err = install_blob(worktree, ondisk_path, path, te->mode,
1239 		    sb.st_mode, blob, status == GOT_STATUS_MISSING, 0,
1240 		    repo, progress_cb, progress_arg);
1241 		if (err)
1242 			goto done;
1243 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1244 		    ondisk_path, path, blob, 1);
1245 		if (err)
1246 			goto done;
1247 	}
1248 	got_object_blob_close(blob);
1249 done:
1250 	free(ondisk_path);
1251 	return err;
1252 }
1253 
1254 static const struct got_error *
1255 remove_ondisk_file(const char *root_path, const char *path)
1256 {
1257 	const struct got_error *err = NULL;
1258 	char *ondisk_path = NULL;
1259 
1260 	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
1261 		return got_error_from_errno("asprintf");
1262 
1263 	if (unlink(ondisk_path) == -1) {
1264 		if (errno != ENOENT)
1265 			err = got_error_from_errno2("unlink", ondisk_path);
1266 	} else {
1267 		char *parent = dirname(ondisk_path);
1268 		while (parent && strcmp(parent, root_path) != 0) {
1269 			if (rmdir(parent) == -1) {
1270 				if (errno != ENOTEMPTY)
1271 					err = got_error_from_errno2("rmdir",
1272 					    parent);
1273 				break;
1274 			}
1275 			parent = dirname(parent);
1276 		}
1277 	}
1278 	free(ondisk_path);
1279 	return err;
1280 }
1281 
1282 static const struct got_error *
1283 delete_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
1284     struct got_fileindex_entry *ie, struct got_repository *repo,
1285     got_worktree_checkout_cb progress_cb, void *progress_arg)
1286 {
1287 	const struct got_error *err = NULL;
1288 	unsigned char status;
1289 	struct stat sb;
1290 	char *ondisk_path;
1291 
1292 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, ie->path)
1293 	    == -1)
1294 		return got_error_from_errno("asprintf");
1295 
1296 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1297 	if (err)
1298 		return err;
1299 
1300 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_CONFLICT ||
1301 	    status == GOT_STATUS_ADD) {
1302 		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, ie->path);
1303 		if (err)
1304 			return err;
1305 		/*
1306 		 * Preserve the working file and change the deleted blob's
1307 		 * entry into a schedule-add entry.
1308 		 */
1309 		err = got_fileindex_entry_update(ie, ondisk_path, NULL, NULL,
1310 		    0);
1311 		if (err)
1312 			return err;
1313 	} else {
1314 		err = (*progress_cb)(progress_arg, GOT_STATUS_DELETE, ie->path);
1315 		if (err)
1316 			return err;
1317 		if (status == GOT_STATUS_NO_CHANGE) {
1318 			err = remove_ondisk_file(worktree->root_path, ie->path);
1319 			if (err)
1320 				return err;
1321 		}
1322 		got_fileindex_entry_remove(fileindex, ie);
1323 	}
1324 
1325 	return err;
1326 }
1327 
1328 struct diff_cb_arg {
1329     struct got_fileindex *fileindex;
1330     struct got_worktree *worktree;
1331     struct got_repository *repo;
1332     got_worktree_checkout_cb progress_cb;
1333     void *progress_arg;
1334     got_worktree_cancel_cb cancel_cb;
1335     void *cancel_arg;
1336 };
1337 
1338 static const struct got_error *
1339 diff_old_new(void *arg, struct got_fileindex_entry *ie,
1340     struct got_tree_entry *te, const char *parent_path)
1341 {
1342 	struct diff_cb_arg *a = arg;
1343 
1344 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1345 		return got_error(GOT_ERR_CANCELLED);
1346 
1347 	return update_blob(a->worktree, a->fileindex, ie, te,
1348 	    ie->path, a->repo, a->progress_cb, a->progress_arg);
1349 }
1350 
1351 static const struct got_error *
1352 diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1353 {
1354 	struct diff_cb_arg *a = arg;
1355 
1356 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1357 		return got_error(GOT_ERR_CANCELLED);
1358 
1359 	return delete_blob(a->worktree, a->fileindex, ie,
1360 	    a->repo, a->progress_cb, a->progress_arg);
1361 }
1362 
1363 static const struct got_error *
1364 diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
1365 {
1366 	struct diff_cb_arg *a = arg;
1367 	const struct got_error *err;
1368 	char *path;
1369 
1370 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1371 		return got_error(GOT_ERR_CANCELLED);
1372 
1373 	if (asprintf(&path, "%s%s%s", parent_path,
1374 	    parent_path[0] ? "/" : "", te->name)
1375 	    == -1)
1376 		return got_error_from_errno("asprintf");
1377 
1378 	if (S_ISDIR(te->mode))
1379 		err = add_dir_on_disk(a->worktree, path);
1380 	else
1381 		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
1382 		    a->repo, a->progress_cb, a->progress_arg);
1383 
1384 	free(path);
1385 	return err;
1386 }
1387 
1388 static const struct got_error *
1389 get_ref_name(char **refname, struct got_worktree *worktree, const char *prefix)
1390 {
1391 	const struct got_error *err = NULL;
1392 	char *uuidstr = NULL;
1393 	uint32_t uuid_status;
1394 
1395 	*refname = NULL;
1396 
1397 	uuid_to_string(&worktree->uuid, &uuidstr, &uuid_status);
1398 	if (uuid_status != uuid_s_ok)
1399 		return got_error_uuid(uuid_status);
1400 
1401 	if (asprintf(refname, "%s-%s", prefix, uuidstr)
1402 	    == -1) {
1403 		err = got_error_from_errno("asprintf");
1404 		*refname = NULL;
1405 	}
1406 	free(uuidstr);
1407 	return err;
1408 }
1409 
1410 const struct got_error *
1411 got_worktree_get_base_ref_name(char **refname, struct got_worktree *worktree)
1412 {
1413 	return get_ref_name(refname, worktree, GOT_WORKTREE_BASE_REF_PREFIX);
1414 }
1415 
1416 static const struct got_error *
1417 get_rebase_tmp_ref_name(char **refname, struct got_worktree *worktree)
1418 {
1419 	return get_ref_name(refname, worktree,
1420 	    GOT_WORKTREE_REBASE_TMP_REF_PREFIX);
1421 }
1422 
1423 static const struct got_error *
1424 get_newbase_symref_name(char **refname, struct got_worktree *worktree)
1425 {
1426 	return get_ref_name(refname, worktree, GOT_WORKTREE_NEWBASE_REF_PREFIX);
1427 }
1428 
1429 static const struct got_error *
1430 get_rebase_branch_symref_name(char **refname, struct got_worktree *worktree)
1431 {
1432 	return get_ref_name(refname, worktree,
1433 	    GOT_WORKTREE_REBASE_BRANCH_REF_PREFIX);
1434 }
1435 
1436 static const struct got_error *
1437 get_rebase_commit_ref_name(char **refname, struct got_worktree *worktree)
1438 {
1439 	return get_ref_name(refname, worktree,
1440 	    GOT_WORKTREE_REBASE_COMMIT_REF_PREFIX);
1441 }
1442 
1443 static const struct got_error *
1444 get_histedit_tmp_ref_name(char **refname, struct got_worktree *worktree)
1445 {
1446 	return get_ref_name(refname, worktree,
1447 	    GOT_WORKTREE_HISTEDIT_TMP_REF_PREFIX);
1448 }
1449 
1450 static const struct got_error *
1451 get_histedit_branch_symref_name(char **refname, struct got_worktree *worktree)
1452 {
1453 	return get_ref_name(refname, worktree,
1454 	    GOT_WORKTREE_HISTEDIT_BRANCH_REF_PREFIX);
1455 }
1456 
1457 static const struct got_error *
1458 get_histedit_base_commit_ref_name(char **refname, struct got_worktree *worktree)
1459 {
1460 	return get_ref_name(refname, worktree,
1461 	    GOT_WORKTREE_HISTEDIT_BASE_COMMIT_REF_PREFIX);
1462 }
1463 
1464 static const struct got_error *
1465 get_histedit_commit_ref_name(char **refname, struct got_worktree *worktree)
1466 {
1467 	return get_ref_name(refname, worktree,
1468 	    GOT_WORKTREE_HISTEDIT_COMMIT_REF_PREFIX);
1469 }
1470 
1471 const struct got_error *
1472 got_worktree_get_histedit_list_path(char **path, struct got_worktree *worktree)
1473 {
1474 	if (asprintf(path, "%s/%s/%s", worktree->root_path,
1475 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_HISTEDIT_LIST) == -1) {
1476 		*path = NULL;
1477 		return got_error_from_errno("asprintf");
1478 	}
1479 	return NULL;
1480 }
1481 
1482 /*
1483  * Prevent Git's garbage collector from deleting our base commit by
1484  * setting a reference to our base commit's ID.
1485  */
1486 static const struct got_error *
1487 ref_base_commit(struct got_worktree *worktree, struct got_repository *repo)
1488 {
1489 	const struct got_error *err = NULL;
1490 	struct got_reference *ref = NULL;
1491 	char *refname;
1492 
1493 	err = got_worktree_get_base_ref_name(&refname, worktree);
1494 	if (err)
1495 		return err;
1496 
1497 	err = got_ref_alloc(&ref, refname, worktree->base_commit_id);
1498 	if (err)
1499 		goto done;
1500 
1501 	err = got_ref_write(ref, repo);
1502 done:
1503 	free(refname);
1504 	if (ref)
1505 		got_ref_close(ref);
1506 	return err;
1507 }
1508 
1509 static const struct got_error *
1510 get_fileindex_path(char **fileindex_path, struct got_worktree *worktree)
1511 {
1512 	const struct got_error *err = NULL;
1513 
1514 	if (asprintf(fileindex_path, "%s/%s/%s", worktree->root_path,
1515 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1516 		err = got_error_from_errno("asprintf");
1517 		*fileindex_path = NULL;
1518 	}
1519 	return err;
1520 }
1521 
1522 
1523 static const struct got_error *
1524 open_fileindex(struct got_fileindex **fileindex, char **fileindex_path,
1525    struct got_worktree *worktree)
1526 {
1527 	const struct got_error *err = NULL;
1528 	FILE *index = NULL;
1529 
1530 	*fileindex_path = NULL;
1531 	*fileindex = got_fileindex_alloc();
1532 	if (*fileindex == NULL)
1533 		return got_error_from_errno("got_fileindex_alloc");
1534 
1535 	err = get_fileindex_path(fileindex_path, worktree);
1536 	if (err)
1537 		goto done;
1538 
1539 	index = fopen(*fileindex_path, "rb");
1540 	if (index == NULL) {
1541 		if (errno != ENOENT)
1542 			err = got_error_from_errno2("fopen", *fileindex_path);
1543 	} else {
1544 		err = got_fileindex_read(*fileindex, index);
1545 		if (fclose(index) != 0 && err == NULL)
1546 			err = got_error_from_errno("fclose");
1547 	}
1548 done:
1549 	if (err) {
1550 		free(*fileindex_path);
1551 		*fileindex_path = NULL;
1552 		got_fileindex_free(*fileindex);
1553 		*fileindex = NULL;
1554 	}
1555 	return err;
1556 }
1557 
1558 struct bump_base_commit_id_arg {
1559 	struct got_object_id *base_commit_id;
1560 	const char *path;
1561 	size_t path_len;
1562 	const char *entry_name;
1563 	got_worktree_checkout_cb progress_cb;
1564 	void *progress_arg;
1565 };
1566 
1567 /* Bump base commit ID of all files within an updated part of the work tree. */
1568 static const struct got_error *
1569 bump_base_commit_id(void *arg, struct got_fileindex_entry *ie)
1570 {
1571 	const struct got_error *err;
1572 	struct bump_base_commit_id_arg *a = arg;
1573 
1574 	if (a->entry_name) {
1575 		if (strcmp(ie->path, a->path) != 0)
1576 			return NULL;
1577 	} else if (!got_path_is_child(ie->path, a->path, a->path_len))
1578 		return NULL;
1579 
1580 	if (memcmp(ie->commit_sha1, a->base_commit_id->sha1,
1581 	    SHA1_DIGEST_LENGTH) == 0)
1582 		return NULL;
1583 
1584 	if (a->progress_cb) {
1585 		err = (*a->progress_cb)(a->progress_arg, GOT_STATUS_BUMP_BASE,
1586 		    ie->path);
1587 		if (err)
1588 			return err;
1589 	}
1590 	memcpy(ie->commit_sha1, a->base_commit_id->sha1, SHA1_DIGEST_LENGTH);
1591 	return NULL;
1592 }
1593 
1594 static const struct got_error *
1595 sync_fileindex(struct got_fileindex *fileindex, const char *fileindex_path)
1596 {
1597 	const struct got_error *err = NULL;
1598 	char *new_fileindex_path = NULL;
1599 	FILE *new_index = NULL;
1600 
1601 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1602 	    fileindex_path);
1603 	if (err)
1604 		goto done;
1605 
1606 	err = got_fileindex_write(fileindex, new_index);
1607 	if (err)
1608 		goto done;
1609 
1610 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1611 		err = got_error_from_errno3("rename", new_fileindex_path,
1612 		    fileindex_path);
1613 		unlink(new_fileindex_path);
1614 	}
1615 done:
1616 	if (new_index)
1617 		fclose(new_index);
1618 	free(new_fileindex_path);
1619 	return err;
1620 }
1621 
1622 static const struct got_error *
1623 find_tree_entry_for_checkout(int *entry_type, char **tree_relpath,
1624     struct got_object_id **tree_id, const char *wt_relpath,
1625     struct got_worktree *worktree, struct got_repository *repo)
1626 {
1627 	const struct got_error *err = NULL;
1628 	struct got_object_id *id = NULL;
1629 	char *in_repo_path = NULL;
1630 	int is_root_wt = got_path_is_root_dir(worktree->path_prefix);
1631 
1632 	*entry_type = GOT_OBJ_TYPE_ANY;
1633 	*tree_relpath = NULL;
1634 	*tree_id = NULL;
1635 
1636 	if (wt_relpath[0] == '\0') {
1637 		/* Check out all files within the work tree. */
1638 		*entry_type = GOT_OBJ_TYPE_TREE;
1639 		*tree_relpath = strdup("");
1640 		if (*tree_relpath == NULL) {
1641 			err = got_error_from_errno("strdup");
1642 			goto done;
1643 		}
1644 		err = got_object_id_by_path(tree_id, repo,
1645 		    worktree->base_commit_id, worktree->path_prefix);
1646 		if (err)
1647 			goto done;
1648 		return NULL;
1649 	}
1650 
1651 	/* Check out a subset of files in the work tree. */
1652 
1653 	if (asprintf(&in_repo_path, "%s%s%s", worktree->path_prefix,
1654 	    is_root_wt ? "" : "/", wt_relpath) == -1) {
1655 		err = got_error_from_errno("asprintf");
1656 		goto done;
1657 	}
1658 
1659 	err = got_object_id_by_path(&id, repo, worktree->base_commit_id,
1660 	    in_repo_path);
1661 	if (err)
1662 		goto done;
1663 
1664 	free(in_repo_path);
1665 	in_repo_path = NULL;
1666 
1667 	err = got_object_get_type(entry_type, repo, id);
1668 	if (err)
1669 		goto done;
1670 
1671 	if (*entry_type == GOT_OBJ_TYPE_BLOB) {
1672 		/* Check out a single file. */
1673 		if (strchr(wt_relpath, '/')  == NULL) {
1674 			/* Check out a single file in work tree's root dir. */
1675 			in_repo_path = strdup(worktree->path_prefix);
1676 			if (in_repo_path == NULL) {
1677 				err = got_error_from_errno("strdup");
1678 				goto done;
1679 			}
1680 			*tree_relpath = strdup("");
1681 			if (*tree_relpath == NULL) {
1682 				err = got_error_from_errno("strdup");
1683 				goto done;
1684 			}
1685 		} else {
1686 			/* Check out a single file in a subdirectory. */
1687 			err = got_path_dirname(tree_relpath, wt_relpath);
1688 			if (err)
1689 				return err;
1690 			if (asprintf(&in_repo_path, "%s%s%s",
1691 			    worktree->path_prefix, is_root_wt ? "" : "/",
1692 			    *tree_relpath) == -1) {
1693 				err = got_error_from_errno("asprintf");
1694 				goto done;
1695 			}
1696 		}
1697 		err = got_object_id_by_path(tree_id, repo,
1698 		    worktree->base_commit_id, in_repo_path);
1699 	} else {
1700 		/* Check out all files within a subdirectory. */
1701 		*tree_id = got_object_id_dup(id);
1702 		if (*tree_id == NULL) {
1703 			err = got_error_from_errno("got_object_id_dup");
1704 			goto done;
1705 		}
1706 		*tree_relpath = strdup(wt_relpath);
1707 		if (*tree_relpath == NULL) {
1708 			err = got_error_from_errno("strdup");
1709 			goto done;
1710 		}
1711 	}
1712 done:
1713 	free(id);
1714 	free(in_repo_path);
1715 	if (err) {
1716 		*entry_type = GOT_OBJ_TYPE_ANY;
1717 		free(*tree_relpath);
1718 		*tree_relpath = NULL;
1719 		free(*tree_id);
1720 		*tree_id = NULL;
1721 	}
1722 	return err;
1723 }
1724 
1725 static const struct got_error *
1726 checkout_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
1727     const char *relpath, struct got_object_id *tree_id, const char *entry_name,
1728     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1729     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1730 {
1731 	const struct got_error *err = NULL;
1732 	struct got_commit_object *commit = NULL;
1733 	struct got_tree_object *tree = NULL;
1734 	struct got_fileindex_diff_tree_cb diff_cb;
1735 	struct diff_cb_arg arg;
1736 
1737 	err = ref_base_commit(worktree, repo);
1738 	if (err)
1739 		goto done;
1740 
1741 	err = got_object_open_as_commit(&commit, repo,
1742 	   worktree->base_commit_id);
1743 	if (err)
1744 		goto done;
1745 
1746 	err = got_object_open_as_tree(&tree, repo, tree_id);
1747 	if (err)
1748 		goto done;
1749 
1750 	if (entry_name &&
1751 	    got_object_tree_find_entry(tree, entry_name) == NULL) {
1752 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
1753 		goto done;
1754 	}
1755 
1756 	diff_cb.diff_old_new = diff_old_new;
1757 	diff_cb.diff_old = diff_old;
1758 	diff_cb.diff_new = diff_new;
1759 	arg.fileindex = fileindex;
1760 	arg.worktree = worktree;
1761 	arg.repo = repo;
1762 	arg.progress_cb = progress_cb;
1763 	arg.progress_arg = progress_arg;
1764 	arg.cancel_cb = cancel_cb;
1765 	arg.cancel_arg = cancel_arg;
1766 	err = got_fileindex_diff_tree(fileindex, tree, relpath,
1767 	    entry_name, repo, &diff_cb, &arg);
1768 done:
1769 	if (tree)
1770 		got_object_tree_close(tree);
1771 	if (commit)
1772 		got_object_commit_close(commit);
1773 	return err;
1774 }
1775 
1776 const struct got_error *
1777 got_worktree_checkout_files(struct got_worktree *worktree, const char *path,
1778     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1779     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1780 {
1781 	const struct got_error *err = NULL, *sync_err, *unlockerr;
1782 	struct got_commit_object *commit = NULL;
1783 	struct got_object_id *tree_id = NULL;
1784 	struct got_tree_object *tree = NULL;
1785 	struct got_fileindex *fileindex = NULL;
1786 	char *fileindex_path = NULL;
1787 	char *relpath = NULL, *entry_name = NULL;
1788 	int entry_type;
1789 
1790 	err = lock_worktree(worktree, LOCK_EX);
1791 	if (err)
1792 		return err;
1793 
1794 	err = find_tree_entry_for_checkout(&entry_type, &relpath, &tree_id,
1795 	    path, worktree, repo);
1796 	if (err)
1797 		goto done;
1798 
1799 	if (entry_type == GOT_OBJ_TYPE_BLOB) {
1800 		entry_name = basename(path);
1801 		if (entry_name == NULL) {
1802 			err = got_error_from_errno2("basename", path);
1803 			goto done;
1804 		}
1805 	}
1806 
1807 	/*
1808 	 * Read the file index.
1809 	 * Checking out files is supposed to be an idempotent operation.
1810 	 * If the on-disk file index is incomplete we will try to complete it.
1811 	 */
1812 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
1813 	if (err)
1814 		goto done;
1815 
1816 	err = checkout_files(worktree, fileindex, relpath, tree_id, entry_name,
1817 	    repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
1818 	if (err == NULL) {
1819 		struct bump_base_commit_id_arg bbc_arg;
1820 		bbc_arg.base_commit_id = worktree->base_commit_id;
1821 		bbc_arg.entry_name = entry_name;
1822 		bbc_arg.path = path;
1823 		bbc_arg.path_len = strlen(path);
1824 		bbc_arg.progress_cb = progress_cb;
1825 		bbc_arg.progress_arg = progress_arg;
1826 		err = got_fileindex_for_each_entry_safe(fileindex,
1827 		    bump_base_commit_id, &bbc_arg);
1828 	}
1829 	sync_err = sync_fileindex(fileindex, fileindex_path);
1830 	if (sync_err && err == NULL)
1831 		err = sync_err;
1832 done:
1833 	free(fileindex_path);
1834 	free(relpath);
1835 	if (tree)
1836 		got_object_tree_close(tree);
1837 	if (commit)
1838 		got_object_commit_close(commit);
1839 	if (fileindex)
1840 		got_fileindex_free(fileindex);
1841 	unlockerr = lock_worktree(worktree, LOCK_SH);
1842 	if (unlockerr && err == NULL)
1843 		err = unlockerr;
1844 	return err;
1845 }
1846 
1847 struct merge_file_cb_arg {
1848     struct got_worktree *worktree;
1849     struct got_fileindex *fileindex;
1850     got_worktree_checkout_cb progress_cb;
1851     void *progress_arg;
1852     got_worktree_cancel_cb cancel_cb;
1853     void *cancel_arg;
1854     struct got_object_id *commit_id2;
1855 };
1856 
1857 static const struct got_error *
1858 merge_file_cb(void *arg, struct got_blob_object *blob1,
1859     struct got_blob_object *blob2, struct got_object_id *id1,
1860     struct got_object_id *id2, const char *path1, const char *path2,
1861     struct got_repository *repo)
1862 {
1863 	static const struct got_error *err = NULL;
1864 	struct merge_file_cb_arg *a = arg;
1865 	struct got_fileindex_entry *ie;
1866 	char *ondisk_path = NULL;
1867 	struct stat sb;
1868 	unsigned char status;
1869 	int local_changes_subsumed;
1870 
1871 	if (blob1 && blob2) {
1872 		ie = got_fileindex_entry_get(a->fileindex, path2);
1873 		if (ie == NULL)
1874 			return (*a->progress_cb)(a->progress_arg,
1875 			    GOT_STATUS_MISSING, path2);
1876 
1877 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1878 		    path2) == -1)
1879 			return got_error_from_errno("asprintf");
1880 
1881 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1882 		if (err)
1883 			goto done;
1884 
1885 		if (status == GOT_STATUS_DELETE) {
1886 			err = (*a->progress_cb)(a->progress_arg,
1887 			    GOT_STATUS_MERGE, path2);
1888 			goto done;
1889 		}
1890 		if (status != GOT_STATUS_NO_CHANGE &&
1891 		    status != GOT_STATUS_MODIFY &&
1892 		    status != GOT_STATUS_CONFLICT &&
1893 		    status != GOT_STATUS_ADD) {
1894 			err = (*a->progress_cb)(a->progress_arg, status, path2);
1895 			goto done;
1896 		}
1897 
1898 		err = merge_blob(&local_changes_subsumed, a->worktree, blob1,
1899 		    ondisk_path, path2, sb.st_mode, blob2, a->commit_id2, repo,
1900 		    a->progress_cb, a->progress_arg);
1901 	} else if (blob1) {
1902 		ie = got_fileindex_entry_get(a->fileindex, path1);
1903 		if (ie == NULL)
1904 			return (*a->progress_cb)(a->progress_arg,
1905 			    GOT_STATUS_MISSING, path2);
1906 
1907 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1908 		    path1) == -1)
1909 			return got_error_from_errno("asprintf");
1910 
1911 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1912 		if (err)
1913 			goto done;
1914 
1915 		switch (status) {
1916 		case GOT_STATUS_NO_CHANGE:
1917 			err = (*a->progress_cb)(a->progress_arg,
1918 			    GOT_STATUS_DELETE, path1);
1919 			if (err)
1920 				goto done;
1921 			err = remove_ondisk_file(a->worktree->root_path, path1);
1922 			if (err)
1923 				goto done;
1924 			if (ie)
1925 				got_fileindex_entry_mark_deleted_from_disk(ie);
1926 			break;
1927 		case GOT_STATUS_DELETE:
1928 		case GOT_STATUS_MISSING:
1929 			err = (*a->progress_cb)(a->progress_arg,
1930 			    GOT_STATUS_DELETE, path1);
1931 			if (err)
1932 				goto done;
1933 			if (ie)
1934 				got_fileindex_entry_mark_deleted_from_disk(ie);
1935 			break;
1936 		case GOT_STATUS_ADD:
1937 		case GOT_STATUS_MODIFY:
1938 		case GOT_STATUS_CONFLICT:
1939 			err = (*a->progress_cb)(a->progress_arg,
1940 			    GOT_STATUS_CANNOT_DELETE, path1);
1941 			if (err)
1942 				goto done;
1943 			break;
1944 		case GOT_STATUS_OBSTRUCTED:
1945 			err = (*a->progress_cb)(a->progress_arg, status, path1);
1946 			if (err)
1947 				goto done;
1948 			break;
1949 		default:
1950 			break;
1951 		}
1952 	} else if (blob2) {
1953 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1954 		    path2) == -1)
1955 			return got_error_from_errno("asprintf");
1956 		ie = got_fileindex_entry_get(a->fileindex, path2);
1957 		if (ie) {
1958 			err = get_file_status(&status, &sb, ie, ondisk_path,
1959 			    repo);
1960 			if (err)
1961 				goto done;
1962 			if (status != GOT_STATUS_NO_CHANGE &&
1963 			    status != GOT_STATUS_MODIFY &&
1964 			    status != GOT_STATUS_CONFLICT &&
1965 			    status != GOT_STATUS_ADD) {
1966 				err = (*a->progress_cb)(a->progress_arg,
1967 				    status, path2);
1968 				goto done;
1969 			}
1970 			err = merge_blob(&local_changes_subsumed, a->worktree,
1971 			    NULL, ondisk_path, path2, sb.st_mode, blob2,
1972 			    a->commit_id2, repo,
1973 			    a->progress_cb, a->progress_arg);
1974 			if (status == GOT_STATUS_DELETE) {
1975 				err = update_blob_fileindex_entry(a->worktree,
1976 				    a->fileindex, ie, ondisk_path, ie->path,
1977 				    blob2, 0);
1978 				if (err)
1979 					goto done;
1980 			}
1981 		} else {
1982 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1983 			err = install_blob(a->worktree, ondisk_path, path2,
1984 			    /* XXX get this from parent tree! */
1985 			    GOT_DEFAULT_FILE_MODE,
1986 			    sb.st_mode, blob2, 0, 0, repo,
1987 			    a->progress_cb, a->progress_arg);
1988 			if (err)
1989 				goto done;
1990 			err = got_fileindex_entry_alloc(&ie,
1991 			    ondisk_path, path2, NULL, NULL);
1992 			if (err)
1993 				goto done;
1994 			err = got_fileindex_entry_add(a->fileindex, ie);
1995 			if (err) {
1996 				got_fileindex_entry_free(ie);
1997 				goto done;
1998 			}
1999 		}
2000 	}
2001 done:
2002 	free(ondisk_path);
2003 	return err;
2004 }
2005 
2006 struct check_merge_ok_arg {
2007 	struct got_worktree *worktree;
2008 	struct got_repository *repo;
2009 };
2010 
2011 static const struct got_error *
2012 check_merge_ok(void *arg, struct got_fileindex_entry *ie)
2013 {
2014 	const struct got_error *err = NULL;
2015 	struct check_merge_ok_arg *a = arg;
2016 	unsigned char status;
2017 	struct stat sb;
2018 	char *ondisk_path;
2019 
2020 	/* Reject merges into a work tree with mixed base commits. */
2021 	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
2022 	    SHA1_DIGEST_LENGTH))
2023 		return got_error(GOT_ERR_MIXED_COMMITS);
2024 
2025 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
2026 	    == -1)
2027 		return got_error_from_errno("asprintf");
2028 
2029 	/* Reject merges into a work tree with conflicted files. */
2030 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
2031 	if (err)
2032 		return err;
2033 	if (status == GOT_STATUS_CONFLICT)
2034 		return got_error(GOT_ERR_CONFLICTS);
2035 
2036 	return NULL;
2037 }
2038 
2039 static const struct got_error *
2040 merge_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
2041     const char *fileindex_path, struct got_object_id *commit_id1,
2042     struct got_object_id *commit_id2, struct got_repository *repo,
2043     got_worktree_checkout_cb progress_cb, void *progress_arg,
2044     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2045 {
2046 	const struct got_error *err = NULL, *sync_err;
2047 	struct got_object_id *tree_id1 = NULL, *tree_id2 = NULL;
2048 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
2049 	struct merge_file_cb_arg arg;
2050 
2051 	if (commit_id1) {
2052 		err = got_object_id_by_path(&tree_id1, repo, commit_id1,
2053 		    worktree->path_prefix);
2054 		if (err)
2055 			goto done;
2056 
2057 		err = got_object_open_as_tree(&tree1, repo, tree_id1);
2058 		if (err)
2059 			goto done;
2060 	}
2061 
2062 	err = got_object_id_by_path(&tree_id2, repo, commit_id2,
2063 	    worktree->path_prefix);
2064 	if (err)
2065 		goto done;
2066 
2067 	err = got_object_open_as_tree(&tree2, repo, tree_id2);
2068 	if (err)
2069 		goto done;
2070 
2071 	arg.worktree = worktree;
2072 	arg.fileindex = fileindex;
2073 	arg.progress_cb = progress_cb;
2074 	arg.progress_arg = progress_arg;
2075 	arg.cancel_cb = cancel_cb;
2076 	arg.cancel_arg = cancel_arg;
2077 	arg.commit_id2 = commit_id2;
2078 	err = got_diff_tree(tree1, tree2, "", "", repo, merge_file_cb, &arg);
2079 	sync_err = sync_fileindex(fileindex, fileindex_path);
2080 	if (sync_err && err == NULL)
2081 		err = sync_err;
2082 done:
2083 	if (tree1)
2084 		got_object_tree_close(tree1);
2085 	if (tree2)
2086 		got_object_tree_close(tree2);
2087 	return err;
2088 }
2089 
2090 const struct got_error *
2091 got_worktree_merge_files(struct got_worktree *worktree,
2092     struct got_object_id *commit_id1, struct got_object_id *commit_id2,
2093     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
2094     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2095 {
2096 	const struct got_error *err, *unlockerr;
2097 	char *fileindex_path = NULL;
2098 	struct got_fileindex *fileindex = NULL;
2099 	struct check_merge_ok_arg mok_arg;
2100 
2101 	err = lock_worktree(worktree, LOCK_EX);
2102 	if (err)
2103 		return err;
2104 
2105 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2106 	if (err)
2107 		goto done;
2108 
2109 	mok_arg.worktree = worktree;
2110 	mok_arg.repo = repo;
2111 	err = got_fileindex_for_each_entry_safe(fileindex, check_merge_ok,
2112 	    &mok_arg);
2113 	if (err)
2114 		goto done;
2115 
2116 	err = merge_files(worktree, fileindex, fileindex_path, commit_id1,
2117 	    commit_id2, repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
2118 done:
2119 	if (fileindex)
2120 		got_fileindex_free(fileindex);
2121 	free(fileindex_path);
2122 	unlockerr = lock_worktree(worktree, LOCK_SH);
2123 	if (unlockerr && err == NULL)
2124 		err = unlockerr;
2125 	return err;
2126 }
2127 
2128 struct diff_dir_cb_arg {
2129     struct got_fileindex *fileindex;
2130     struct got_worktree *worktree;
2131     const char *status_path;
2132     size_t status_path_len;
2133     struct got_repository *repo;
2134     got_worktree_status_cb status_cb;
2135     void *status_arg;
2136     got_worktree_cancel_cb cancel_cb;
2137     void *cancel_arg;
2138 };
2139 
2140 static const struct got_error *
2141 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
2142     got_worktree_status_cb status_cb, void *status_arg,
2143     struct got_repository *repo)
2144 {
2145 	const struct got_error *err = NULL;
2146 	unsigned char status = GOT_STATUS_NO_CHANGE;
2147 	struct stat sb;
2148 	struct got_object_id blob_id, commit_id;
2149 
2150 	err = get_file_status(&status, &sb, ie, abspath, repo);
2151 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
2152 		memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2153 		memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2154 		err = (*status_cb)(status_arg, status, ie->path, &blob_id,
2155 		    &commit_id);
2156 	}
2157 	return err;
2158 }
2159 
2160 static const struct got_error *
2161 status_old_new(void *arg, struct got_fileindex_entry *ie,
2162     struct dirent *de, const char *parent_path)
2163 {
2164 	const struct got_error *err = NULL;
2165 	struct diff_dir_cb_arg *a = arg;
2166 	char *abspath;
2167 
2168 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2169 		return got_error(GOT_ERR_CANCELLED);
2170 
2171 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
2172 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
2173 		return NULL;
2174 
2175 	if (parent_path[0]) {
2176 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
2177 		    parent_path, de->d_name) == -1)
2178 			return got_error_from_errno("asprintf");
2179 	} else {
2180 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
2181 		    de->d_name) == -1)
2182 			return got_error_from_errno("asprintf");
2183 	}
2184 
2185 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
2186 	    a->repo);
2187 	free(abspath);
2188 	return err;
2189 }
2190 
2191 static const struct got_error *
2192 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
2193 {
2194 	struct diff_dir_cb_arg *a = arg;
2195 	struct got_object_id blob_id, commit_id;
2196 	unsigned char status;
2197 
2198 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2199 		return got_error(GOT_ERR_CANCELLED);
2200 
2201 	if (!got_path_is_child(ie->path, a->status_path, a->status_path_len))
2202 		return NULL;
2203 
2204 	memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2205 	memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2206 	if (got_fileindex_entry_has_file_on_disk(ie))
2207 		status = GOT_STATUS_MISSING;
2208 	else
2209 		status = GOT_STATUS_DELETE;
2210 	return (*a->status_cb)(a->status_arg, status, ie->path, &blob_id,
2211 	    &commit_id);
2212 }
2213 
2214 static const struct got_error *
2215 status_new(void *arg, struct dirent *de, const char *parent_path)
2216 {
2217 	const struct got_error *err = NULL;
2218 	struct diff_dir_cb_arg *a = arg;
2219 	char *path = NULL;
2220 
2221 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2222 		return got_error(GOT_ERR_CANCELLED);
2223 
2224 	if (de->d_type == DT_DIR)
2225 		return NULL;
2226 
2227 	/* XXX ignore symlinks for now */
2228 	if (de->d_type == DT_LNK)
2229 		return NULL;
2230 
2231 	if (parent_path[0]) {
2232 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
2233 			return got_error_from_errno("asprintf");
2234 	} else {
2235 		path = de->d_name;
2236 	}
2237 
2238 	if (got_path_is_child(path, a->status_path, a->status_path_len))
2239 		err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED,
2240 		    path, NULL, NULL);
2241 	if (parent_path[0])
2242 		free(path);
2243 	return err;
2244 }
2245 
2246 static const struct got_error *
2247 worktree_status(struct got_worktree *worktree, const char *path,
2248     struct got_fileindex *fileindex, struct got_repository *repo,
2249     got_worktree_status_cb status_cb, void *status_arg,
2250     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2251 {
2252 	const struct got_error *err = NULL;
2253 	DIR *workdir = NULL;
2254 	struct got_fileindex_diff_dir_cb fdiff_cb;
2255 	struct diff_dir_cb_arg arg;
2256 	char *ondisk_path = NULL;
2257 
2258 	if (asprintf(&ondisk_path, "%s%s%s",
2259 	    worktree->root_path, path[0] ? "/" : "", path) == -1) {
2260 		err = got_error_from_errno("asprintf");
2261 		goto done;
2262 	}
2263 	workdir = opendir(ondisk_path);
2264 	if (workdir == NULL) {
2265 		if (errno == ENOTDIR || errno == ENOENT) {
2266 			struct got_fileindex_entry *ie;
2267 			ie = got_fileindex_entry_get(fileindex, path);
2268 			if (ie == NULL)
2269 				err = (*status_cb)(status_arg,
2270 				    GOT_STATUS_UNVERSIONED, path, NULL, NULL);
2271 			else
2272 				err = report_file_status(ie, ondisk_path,
2273 				    status_cb, status_arg, repo);
2274 			if (err)
2275 				goto done;
2276 			err = report_file_status(ie, ondisk_path,
2277 			    status_cb, status_arg, repo);
2278 			goto done;
2279 		} else {
2280 			err = got_error_from_errno2("opendir", ondisk_path);
2281 			goto done;
2282 		}
2283 	}
2284 	fdiff_cb.diff_old_new = status_old_new;
2285 	fdiff_cb.diff_old = status_old;
2286 	fdiff_cb.diff_new = status_new;
2287 	arg.fileindex = fileindex;
2288 	arg.worktree = worktree;
2289 	arg.status_path = path;
2290 	arg.status_path_len = strlen(path);
2291 	arg.repo = repo;
2292 	arg.status_cb = status_cb;
2293 	arg.status_arg = status_arg;
2294 	arg.cancel_cb = cancel_cb;
2295 	arg.cancel_arg = cancel_arg;
2296 	err = got_fileindex_diff_dir(fileindex, workdir, worktree->root_path,
2297 	    path, repo, &fdiff_cb, &arg);
2298 done:
2299 	if (workdir)
2300 		closedir(workdir);
2301 	free(ondisk_path);
2302 	return err;
2303 }
2304 
2305 const struct got_error *
2306 got_worktree_status(struct got_worktree *worktree,
2307     struct got_pathlist_head *paths, struct got_repository *repo,
2308     got_worktree_status_cb status_cb, void *status_arg,
2309     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2310 {
2311 	const struct got_error *err = NULL;
2312 	char *fileindex_path = NULL;
2313 	struct got_fileindex *fileindex = NULL;
2314 	struct got_pathlist_entry *pe;
2315 
2316 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2317 	if (err)
2318 		return err;
2319 
2320 	TAILQ_FOREACH(pe, paths, entry) {
2321 		err = worktree_status(worktree, pe->path, fileindex, repo,
2322 			status_cb, status_arg, cancel_cb, cancel_arg);
2323 		if (err)
2324 			break;
2325 	}
2326 	free(fileindex_path);
2327 	got_fileindex_free(fileindex);
2328 	return err;
2329 }
2330 
2331 const struct got_error *
2332 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
2333     const char *arg)
2334 {
2335 	const struct got_error *err = NULL;
2336 	char *resolved, *cwd = NULL, *path = NULL;
2337 	size_t len;
2338 
2339 	*wt_path = NULL;
2340 
2341 	resolved = realpath(arg, NULL);
2342 	if (resolved == NULL) {
2343 		if (errno != ENOENT)
2344 			return got_error_from_errno2("realpath", arg);
2345 		cwd = getcwd(NULL, 0);
2346 		if (cwd == NULL)
2347 			return got_error_from_errno("getcwd");
2348 		if (asprintf(&resolved, "%s/%s", cwd, arg) == -1) {
2349 			err = got_error_from_errno("asprintf");
2350 			goto done;
2351 		}
2352 	}
2353 
2354 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
2355 	    strlen(got_worktree_get_root_path(worktree)))) {
2356 		err = got_error(GOT_ERR_BAD_PATH);
2357 		goto done;
2358 	}
2359 
2360 	if (strlen(resolved) > strlen(got_worktree_get_root_path(worktree))) {
2361 		err = got_path_skip_common_ancestor(&path,
2362 		    got_worktree_get_root_path(worktree), resolved);
2363 		if (err)
2364 			goto done;
2365 	} else {
2366 		path = strdup("");
2367 		if (path == NULL) {
2368 			err = got_error_from_errno("strdup");
2369 			goto done;
2370 		}
2371 	}
2372 
2373 	/* XXX status walk can't deal with trailing slash! */
2374 	len = strlen(path);
2375 	while (len > 0 && path[len - 1] == '/') {
2376 		path[len - 1] = '\0';
2377 		len--;
2378 	}
2379 done:
2380 	free(resolved);
2381 	free(cwd);
2382 	if (err == NULL)
2383 		*wt_path = path;
2384 	else
2385 		free(path);
2386 	return err;
2387 }
2388 
2389 static const struct got_error *
2390 schedule_addition(const char *ondisk_path, struct got_fileindex *fileindex,
2391     const char *relpath, got_worktree_status_cb status_cb, void *status_arg,
2392     struct got_repository *repo)
2393 {
2394 	const struct got_error *err = NULL;
2395 	struct got_fileindex_entry *ie;
2396 
2397 	/* Re-adding an existing entry is a no-op. */
2398 	if (got_fileindex_entry_get(fileindex, relpath) != NULL)
2399 		return NULL;
2400 
2401 	err = got_fileindex_entry_alloc(&ie, ondisk_path, relpath, NULL, NULL);
2402 	if (err)
2403 		return err;
2404 
2405 	err = got_fileindex_entry_add(fileindex, ie);
2406 	if (err) {
2407 		got_fileindex_entry_free(ie);
2408 		return err;
2409 	}
2410 
2411 	return report_file_status(ie, relpath, status_cb, status_arg, repo);
2412 }
2413 
2414 const struct got_error *
2415 got_worktree_schedule_add(struct got_worktree *worktree,
2416     struct got_pathlist_head *ondisk_paths,
2417     got_worktree_status_cb status_cb, void *status_arg,
2418     struct got_repository *repo)
2419 {
2420 	struct got_fileindex *fileindex = NULL;
2421 	char *fileindex_path = NULL;
2422 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2423 	struct got_pathlist_entry *pe;
2424 
2425 	err = lock_worktree(worktree, LOCK_EX);
2426 	if (err)
2427 		return err;
2428 
2429 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2430 	if (err)
2431 		goto done;
2432 
2433 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2434 		char *relpath;
2435 		err = got_path_skip_common_ancestor(&relpath,
2436 		    got_worktree_get_root_path(worktree), pe->path);
2437 		if (err)
2438 			break;
2439 		err = schedule_addition(pe->path, fileindex, relpath,
2440 		    status_cb, status_arg, repo);
2441 		free(relpath);
2442 		if (err)
2443 			break;
2444 	}
2445 	sync_err = sync_fileindex(fileindex, fileindex_path);
2446 	if (sync_err && err == NULL)
2447 		err = sync_err;
2448 done:
2449 	free(fileindex_path);
2450 	if (fileindex)
2451 		got_fileindex_free(fileindex);
2452 	unlockerr = lock_worktree(worktree, LOCK_SH);
2453 	if (unlockerr && err == NULL)
2454 		err = unlockerr;
2455 	return err;
2456 }
2457 
2458 static const struct got_error *
2459 schedule_for_deletion(const char *ondisk_path, struct got_fileindex *fileindex,
2460     const char *relpath, int delete_local_mods,
2461     got_worktree_status_cb status_cb, void *status_arg,
2462     struct got_repository *repo)
2463 {
2464 	const struct got_error *err = NULL;
2465 	struct got_fileindex_entry *ie = NULL;
2466 	unsigned char status;
2467 	struct stat sb;
2468 
2469 	ie = got_fileindex_entry_get(fileindex, relpath);
2470 	if (ie == NULL)
2471 		return got_error(GOT_ERR_BAD_PATH);
2472 
2473 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2474 	if (err)
2475 		return err;
2476 
2477 	if (status != GOT_STATUS_NO_CHANGE) {
2478 		if (status == GOT_STATUS_DELETE)
2479 			return got_error_set_errno(ENOENT, ondisk_path);
2480 		if (status != GOT_STATUS_MODIFY)
2481 			return got_error(GOT_ERR_FILE_STATUS);
2482 		if (!delete_local_mods)
2483 			return got_error(GOT_ERR_FILE_MODIFIED);
2484 	}
2485 
2486 	if (unlink(ondisk_path) != 0)
2487 		return got_error_from_errno2("unlink", ondisk_path);
2488 
2489 	got_fileindex_entry_mark_deleted_from_disk(ie);
2490 	return report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2491 }
2492 
2493 const struct got_error *
2494 got_worktree_schedule_delete(struct got_worktree *worktree,
2495     struct got_pathlist_head *ondisk_paths, int delete_local_mods,
2496     got_worktree_status_cb status_cb, void *status_arg,
2497     struct got_repository *repo)
2498 {
2499 	struct got_fileindex *fileindex = NULL;
2500 	char *fileindex_path = NULL;
2501 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2502 	struct got_pathlist_entry *pe;
2503 
2504 	err = lock_worktree(worktree, LOCK_EX);
2505 	if (err)
2506 		return err;
2507 
2508 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2509 	if (err)
2510 		goto done;
2511 
2512 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2513 		char *relpath;
2514 		err = got_path_skip_common_ancestor(&relpath,
2515 		    got_worktree_get_root_path(worktree), pe->path);
2516 		if (err)
2517 			break;
2518 		err = schedule_for_deletion(pe->path, fileindex, relpath,
2519 		    delete_local_mods, status_cb, status_arg, repo);
2520 		free(relpath);
2521 		if (err)
2522 			break;
2523 	}
2524 	sync_err = sync_fileindex(fileindex, fileindex_path);
2525 	if (sync_err && err == NULL)
2526 		err = sync_err;
2527 done:
2528 	free(fileindex_path);
2529 	if (fileindex)
2530 		got_fileindex_free(fileindex);
2531 	unlockerr = lock_worktree(worktree, LOCK_SH);
2532 	if (unlockerr && err == NULL)
2533 		err = unlockerr;
2534 	return err;
2535 }
2536 
2537 static const struct got_error *
2538 revert_file(struct got_worktree *worktree, struct got_fileindex *fileindex,
2539     const char *ondisk_path,
2540     got_worktree_checkout_cb progress_cb, void *progress_arg,
2541     struct got_repository *repo)
2542 {
2543 	const struct got_error *err = NULL;
2544 	char *relpath = NULL, *parent_path = NULL;
2545 	struct got_fileindex_entry *ie;
2546 	struct got_tree_object *tree = NULL;
2547 	struct got_object_id *tree_id = NULL;
2548 	const struct got_tree_entry *te;
2549 	char *tree_path = NULL, *te_name;
2550 	struct got_blob_object *blob = NULL;
2551 	unsigned char status;
2552 	struct stat sb;
2553 
2554 	err = got_path_skip_common_ancestor(&relpath,
2555 	    got_worktree_get_root_path(worktree), ondisk_path);
2556 	if (err)
2557 		goto done;
2558 
2559 	ie = got_fileindex_entry_get(fileindex, relpath);
2560 	if (ie == NULL) {
2561 		err = got_error(GOT_ERR_BAD_PATH);
2562 		goto done;
2563 	}
2564 
2565 	/* Construct in-repository path of tree which contains this blob. */
2566 	err = got_path_dirname(&parent_path, ie->path);
2567 	if (err) {
2568 		if (err->code != GOT_ERR_BAD_PATH)
2569 			goto done;
2570 		parent_path = strdup("/");
2571 		if (parent_path == NULL) {
2572 			err = got_error_from_errno("strdup");
2573 			goto done;
2574 		}
2575 	}
2576 	if (got_path_is_root_dir(worktree->path_prefix)) {
2577 		tree_path = strdup(parent_path);
2578 		if (tree_path == NULL) {
2579 			err = got_error_from_errno("strdup");
2580 			goto done;
2581 		}
2582 	} else {
2583 		if (got_path_is_root_dir(parent_path)) {
2584 			tree_path = strdup(worktree->path_prefix);
2585 			if (tree_path == NULL) {
2586 				err = got_error_from_errno("strdup");
2587 				goto done;
2588 			}
2589 		} else {
2590 			if (asprintf(&tree_path, "%s/%s",
2591 			    worktree->path_prefix, parent_path) == -1) {
2592 				err = got_error_from_errno("asprintf");
2593 				goto done;
2594 			}
2595 		}
2596 	}
2597 
2598 	err = got_object_id_by_path(&tree_id, repo, worktree->base_commit_id,
2599 	    tree_path);
2600 	if (err)
2601 		goto done;
2602 
2603 	err = got_object_open_as_tree(&tree, repo, tree_id);
2604 	if (err)
2605 		goto done;
2606 
2607 	te_name = basename(ie->path);
2608 	if (te_name == NULL) {
2609 		err = got_error_from_errno2("basename", ie->path);
2610 		goto done;
2611 	}
2612 
2613 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2614 	if (err)
2615 		goto done;
2616 
2617 	te = got_object_tree_find_entry(tree, te_name);
2618 	if (te == NULL && status != GOT_STATUS_ADD) {
2619 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
2620 		goto done;
2621 	}
2622 
2623 	switch (status) {
2624 	case GOT_STATUS_ADD:
2625 		err = (*progress_cb)(progress_arg, GOT_STATUS_REVERT, ie->path);
2626 		if (err)
2627 			goto done;
2628 		got_fileindex_entry_remove(fileindex, ie);
2629 		break;
2630 	case GOT_STATUS_DELETE:
2631 	case GOT_STATUS_MODIFY:
2632 	case GOT_STATUS_CONFLICT:
2633 	case GOT_STATUS_MISSING: {
2634 		struct got_object_id id;
2635 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2636 		err = got_object_open_as_blob(&blob, repo, &id, 8192);
2637 		if (err)
2638 			goto done;
2639 		err = install_blob(worktree, ondisk_path, ie->path,
2640 		    te->mode, sb.st_mode, blob, 0, 1, repo, progress_cb,
2641 		    progress_arg);
2642 		if (err)
2643 			goto done;
2644 		if (status == GOT_STATUS_DELETE) {
2645 			err = update_blob_fileindex_entry(worktree,
2646 			    fileindex, ie, ondisk_path, ie->path, blob, 1);
2647 			if (err)
2648 				goto done;
2649 		}
2650 		break;
2651 	}
2652 	default:
2653 			goto done;
2654 	}
2655 done:
2656 	free(relpath);
2657 	free(parent_path);
2658 	free(tree_path);
2659 	if (blob)
2660 		got_object_blob_close(blob);
2661 	if (tree)
2662 		got_object_tree_close(tree);
2663 	free(tree_id);
2664 	return err;
2665 }
2666 
2667 const struct got_error *
2668 got_worktree_revert(struct got_worktree *worktree,
2669     struct got_pathlist_head *ondisk_paths,
2670     got_worktree_checkout_cb progress_cb, void *progress_arg,
2671     struct got_repository *repo)
2672 {
2673 	struct got_fileindex *fileindex = NULL;
2674 	char *fileindex_path = NULL;
2675 	const struct got_error *err = NULL, *unlockerr = NULL;
2676 	const struct got_error *sync_err = NULL;
2677 	struct got_pathlist_entry *pe;
2678 
2679 	err = lock_worktree(worktree, LOCK_EX);
2680 	if (err)
2681 		return err;
2682 
2683 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2684 	if (err)
2685 		goto done;
2686 
2687 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2688 		err = revert_file(worktree, fileindex, pe->path,
2689 		    progress_cb, progress_arg, repo);
2690 		if (err)
2691 			break;
2692 	}
2693 	sync_err = sync_fileindex(fileindex, fileindex_path);
2694 	if (sync_err && err == NULL)
2695 		err = sync_err;
2696 done:
2697 	free(fileindex_path);
2698 	if (fileindex)
2699 		got_fileindex_free(fileindex);
2700 	unlockerr = lock_worktree(worktree, LOCK_SH);
2701 	if (unlockerr && err == NULL)
2702 		err = unlockerr;
2703 	return err;
2704 }
2705 
2706 static void
2707 free_commitable(struct got_commitable *ct)
2708 {
2709 	free(ct->path);
2710 	free(ct->in_repo_path);
2711 	free(ct->ondisk_path);
2712 	free(ct->blob_id);
2713 	free(ct->base_blob_id);
2714 	free(ct->base_commit_id);
2715 	free(ct);
2716 }
2717 
2718 struct collect_commitables_arg {
2719 	struct got_pathlist_head *commitable_paths;
2720 	struct got_repository *repo;
2721 	struct got_worktree *worktree;
2722 };
2723 
2724 static const struct got_error *
2725 collect_commitables(void *arg, unsigned char status, const char *relpath,
2726     struct got_object_id *blob_id, struct got_object_id *commit_id)
2727 {
2728 	struct collect_commitables_arg *a = arg;
2729 	const struct got_error *err = NULL;
2730 	struct got_commitable *ct = NULL;
2731 	struct got_pathlist_entry *new = NULL;
2732 	char *parent_path = NULL, *path = NULL;
2733 	struct stat sb;
2734 
2735 	if (status == GOT_STATUS_CONFLICT)
2736 		return got_error(GOT_ERR_COMMIT_CONFLICT);
2737 
2738 	if (status != GOT_STATUS_MODIFY && status != GOT_STATUS_ADD &&
2739 	    status != GOT_STATUS_DELETE)
2740 		return NULL;
2741 
2742 	if (asprintf(&path, "/%s", relpath) == -1) {
2743 		err = got_error_from_errno("asprintf");
2744 		goto done;
2745 	}
2746 	if (strcmp(path, "/") == 0) {
2747 		parent_path = strdup("");
2748 		if (parent_path == NULL)
2749 			return got_error_from_errno("strdup");
2750 	} else {
2751 		err = got_path_dirname(&parent_path, path);
2752 		if (err)
2753 			return err;
2754 	}
2755 
2756 	ct = calloc(1, sizeof(*ct));
2757 	if (ct == NULL) {
2758 		err = got_error_from_errno("calloc");
2759 		goto done;
2760 	}
2761 
2762 	if (asprintf(&ct->ondisk_path, "%s/%s", a->worktree->root_path,
2763 	    relpath) == -1) {
2764 		err = got_error_from_errno("asprintf");
2765 		goto done;
2766 	}
2767 	if (status == GOT_STATUS_DELETE) {
2768 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
2769 	} else {
2770 		if (lstat(ct->ondisk_path, &sb) != 0) {
2771 			err = got_error_from_errno2("lstat", ct->ondisk_path);
2772 			goto done;
2773 		}
2774 		ct->mode = sb.st_mode;
2775 	}
2776 
2777 	if (asprintf(&ct->in_repo_path, "%s%s%s", a->worktree->path_prefix,
2778 	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
2779 	    relpath) == -1) {
2780 		err = got_error_from_errno("asprintf");
2781 		goto done;
2782 	}
2783 
2784 	ct->status = status;
2785 	ct->blob_id = NULL; /* will be filled in when blob gets created */
2786 	if (ct->status != GOT_STATUS_ADD) {
2787 		ct->base_blob_id = got_object_id_dup(blob_id);
2788 		if (ct->base_blob_id == NULL) {
2789 			err = got_error_from_errno("got_object_id_dup");
2790 			goto done;
2791 		}
2792 		ct->base_commit_id = got_object_id_dup(commit_id);
2793 		if (ct->base_commit_id == NULL) {
2794 			err = got_error_from_errno("got_object_id_dup");
2795 			goto done;
2796 		}
2797 	}
2798 	ct->path = strdup(path);
2799 	if (ct->path == NULL) {
2800 		err = got_error_from_errno("strdup");
2801 		goto done;
2802 	}
2803 	err = got_pathlist_insert(&new, a->commitable_paths, ct->path, ct);
2804 done:
2805 	if (ct && (err || new == NULL))
2806 		free_commitable(ct);
2807 	free(parent_path);
2808 	free(path);
2809 	return err;
2810 }
2811 
2812 static const struct got_error *write_tree(struct got_object_id **,
2813     struct got_tree_object *, const char *, struct got_pathlist_head *,
2814     got_worktree_status_cb status_cb, void *status_arg,
2815     struct got_repository *);
2816 
2817 static const struct got_error *
2818 write_subtree(struct got_object_id **new_subtree_id,
2819     struct got_tree_entry *te, const char *parent_path,
2820     struct got_pathlist_head *commitable_paths,
2821     got_worktree_status_cb status_cb, void *status_arg,
2822     struct got_repository *repo)
2823 {
2824 	const struct got_error *err = NULL;
2825 	struct got_tree_object *subtree;
2826 	char *subpath;
2827 
2828 	if (asprintf(&subpath, "%s%s%s", parent_path,
2829 	    got_path_is_root_dir(parent_path) ? "" : "/", te->name) == -1)
2830 		return got_error_from_errno("asprintf");
2831 
2832 	err = got_object_open_as_tree(&subtree, repo, te->id);
2833 	if (err)
2834 		return err;
2835 
2836 	err = write_tree(new_subtree_id, subtree, subpath, commitable_paths,
2837 	    status_cb, status_arg, repo);
2838 	got_object_tree_close(subtree);
2839 	free(subpath);
2840 	return err;
2841 }
2842 
2843 static const struct got_error *
2844 match_ct_parent_path(int *match, struct got_commitable *ct, const char *path)
2845 {
2846 	const struct got_error *err = NULL;
2847 	char *ct_parent_path = NULL;
2848 
2849 	*match = 0;
2850 
2851 	if (strchr(ct->in_repo_path, '/') == NULL) {
2852 		*match = got_path_is_root_dir(path);
2853 		return NULL;
2854 	}
2855 
2856 	err = got_path_dirname(&ct_parent_path, ct->in_repo_path);
2857 	if (err)
2858 		return err;
2859 	*match = (strcmp(path, ct_parent_path) == 0);
2860 	free(ct_parent_path);
2861 	return err;
2862 }
2863 
2864 static mode_t
2865 get_ct_file_mode(struct got_commitable *ct)
2866 {
2867 	return S_IFREG | (ct->mode & ((S_IRWXU | S_IRWXG | S_IRWXO)));
2868 }
2869 
2870 static const struct got_error *
2871 alloc_modified_blob_tree_entry(struct got_tree_entry **new_te,
2872     struct got_tree_entry *te, struct got_commitable *ct)
2873 {
2874 	const struct got_error *err = NULL;
2875 
2876 	*new_te = NULL;
2877 
2878 	err = got_object_tree_entry_dup(new_te, te);
2879 	if (err)
2880 		goto done;
2881 
2882 	(*new_te)->mode = get_ct_file_mode(ct);
2883 
2884 	free((*new_te)->id);
2885 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2886 	if ((*new_te)->id == NULL) {
2887 		err = got_error_from_errno("got_object_id_dup");
2888 		goto done;
2889 	}
2890 done:
2891 	if (err && *new_te) {
2892 		got_object_tree_entry_close(*new_te);
2893 		*new_te = NULL;
2894 	}
2895 	return err;
2896 }
2897 
2898 static const struct got_error *
2899 alloc_added_blob_tree_entry(struct got_tree_entry **new_te,
2900     struct got_commitable *ct)
2901 {
2902 	const struct got_error *err = NULL;
2903 	char *ct_name;
2904 
2905 	 *new_te = NULL;
2906 
2907 	*new_te = calloc(1, sizeof(**new_te));
2908 	if (*new_te == NULL)
2909 		return got_error_from_errno("calloc");
2910 
2911 	ct_name = basename(ct->path);
2912 	if (ct_name == NULL) {
2913 		err = got_error_from_errno2("basename", ct->path);
2914 		goto done;
2915 	}
2916 	(*new_te)->name = strdup(ct_name);
2917 	if ((*new_te)->name == NULL) {
2918 		err = got_error_from_errno("strdup");
2919 		goto done;
2920 	}
2921 
2922 	(*new_te)->mode = get_ct_file_mode(ct);
2923 
2924 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2925 	if ((*new_te)->id == NULL) {
2926 		err = got_error_from_errno("got_object_id_dup");
2927 		goto done;
2928 	}
2929 done:
2930 	if (err && *new_te) {
2931 		got_object_tree_entry_close(*new_te);
2932 		*new_te = NULL;
2933 	}
2934 	return err;
2935 }
2936 
2937 static const struct got_error *
2938 insert_tree_entry(struct got_tree_entry *new_te,
2939     struct got_pathlist_head *paths)
2940 {
2941 	const struct got_error *err = NULL;
2942 	struct got_pathlist_entry *new_pe;
2943 
2944 	err = got_pathlist_insert(&new_pe, paths, new_te->name, new_te);
2945 	if (err)
2946 		return err;
2947 	if (new_pe == NULL)
2948 		return got_error(GOT_ERR_TREE_DUP_ENTRY);
2949 	return NULL;
2950 }
2951 
2952 static const struct got_error *
2953 report_ct_status(struct got_commitable *ct,
2954     got_worktree_status_cb status_cb, void *status_arg)
2955 {
2956 	const char *ct_path = ct->path;
2957 	while (ct_path[0] == '/')
2958 		ct_path++;
2959 	return (*status_cb)(status_arg, ct->status, ct_path, ct->blob_id, NULL);
2960 }
2961 
2962 static const struct got_error *
2963 match_modified_subtree(int *modified, struct got_tree_entry *te,
2964     const char *base_tree_path, struct got_pathlist_head *commitable_paths)
2965 {
2966 	const struct got_error *err = NULL;
2967 	struct got_pathlist_entry *pe;
2968 	char *te_path;
2969 
2970 	*modified = 0;
2971 
2972 	if (asprintf(&te_path, "%s%s%s", base_tree_path,
2973 	    got_path_is_root_dir(base_tree_path) ? "" : "/",
2974 	    te->name) == -1)
2975 		return got_error_from_errno("asprintf");
2976 
2977 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2978 		struct got_commitable *ct = pe->data;
2979 		*modified = got_path_is_child(ct->in_repo_path, te_path,
2980 		    strlen(te_path));
2981 		 if (*modified)
2982 			break;
2983 	}
2984 
2985 	free(te_path);
2986 	return err;
2987 }
2988 
2989 static const struct got_error *
2990 match_deleted_or_modified_ct(struct got_commitable **ctp,
2991     struct got_tree_entry *te, const char *base_tree_path,
2992     struct got_pathlist_head *commitable_paths)
2993 {
2994 	const struct got_error *err = NULL;
2995 	struct got_pathlist_entry *pe;
2996 
2997 	*ctp = NULL;
2998 
2999 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3000 		struct got_commitable *ct = pe->data;
3001 		char *ct_name = NULL;
3002 		int path_matches;
3003 
3004 		if (ct->status != GOT_STATUS_MODIFY &&
3005 		    ct->status != GOT_STATUS_DELETE)
3006 			continue;
3007 
3008 		if (got_object_id_cmp(ct->base_blob_id, te->id) != 0)
3009 			continue;
3010 
3011 		 err = match_ct_parent_path(&path_matches, ct, base_tree_path);
3012 		 if (err)
3013 			return err;
3014 		if (!path_matches)
3015 			continue;
3016 
3017 		ct_name = basename(pe->path);
3018 		if (ct_name == NULL)
3019 			return got_error_from_errno2("basename", pe->path);
3020 
3021 		if (strcmp(te->name, ct_name) != 0)
3022 			continue;
3023 
3024 		*ctp = ct;
3025 		break;
3026 	}
3027 
3028 	return err;
3029 }
3030 
3031 static const struct got_error *
3032 make_subtree_for_added_blob(struct got_tree_entry **new_tep,
3033     const char *child_path, const char *path_base_tree,
3034     struct got_pathlist_head *commitable_paths,
3035     got_worktree_status_cb status_cb, void *status_arg,
3036     struct got_repository *repo)
3037 {
3038 	const struct got_error *err = NULL;
3039 	struct got_tree_entry *new_te;
3040 	char *subtree_path;
3041 
3042 	*new_tep = NULL;
3043 
3044 	if (asprintf(&subtree_path, "%s%s%s", path_base_tree,
3045 	    got_path_is_root_dir(path_base_tree) ? "" : "/",
3046 	    child_path) == -1)
3047 		return got_error_from_errno("asprintf");
3048 
3049 	new_te = calloc(1, sizeof(*new_te));
3050 	new_te->mode = S_IFDIR;
3051 	new_te->name = strdup(child_path);
3052 	if (new_te->name == NULL) {
3053 		err = got_error_from_errno("strdup");
3054 		got_object_tree_entry_close(new_te);
3055 		goto done;
3056 	}
3057 	err = write_tree(&new_te->id, NULL, subtree_path,
3058 	    commitable_paths, status_cb, status_arg, repo);
3059 	if (err) {
3060 		got_object_tree_entry_close(new_te);
3061 		goto done;
3062 	}
3063 done:
3064 	free(subtree_path);
3065 	if (err == NULL)
3066 		*new_tep = new_te;
3067 	return err;
3068 }
3069 
3070 static const struct got_error *
3071 write_tree(struct got_object_id **new_tree_id,
3072     struct got_tree_object *base_tree, const char *path_base_tree,
3073     struct got_pathlist_head *commitable_paths,
3074     got_worktree_status_cb status_cb, void *status_arg,
3075     struct got_repository *repo)
3076 {
3077 	const struct got_error *err = NULL;
3078 	const struct got_tree_entries *base_entries = NULL;
3079 	struct got_pathlist_head paths;
3080 	struct got_tree_entries new_tree_entries;
3081 	struct got_tree_entry *te, *new_te = NULL;
3082 	struct got_pathlist_entry *pe;
3083 
3084 	TAILQ_INIT(&paths);
3085 	new_tree_entries.nentries = 0;
3086 	SIMPLEQ_INIT(&new_tree_entries.head);
3087 
3088 	/* Insert, and recurse into, newly added entries first. */
3089 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3090 		struct got_commitable *ct = pe->data;
3091 		char *child_path = NULL, *slash;
3092 
3093 		if (ct->status != GOT_STATUS_ADD ||
3094 		    (ct->flags & GOT_COMMITABLE_ADDED))
3095 			continue;
3096 
3097 		 if (!got_path_is_child(pe->path, path_base_tree,
3098 		     strlen(path_base_tree)))
3099 			continue;
3100 
3101 		err = got_path_skip_common_ancestor(&child_path, path_base_tree,
3102 		    pe->path);
3103 		if (err)
3104 			goto done;
3105 
3106 		slash = strchr(child_path, '/');
3107 		if (slash == NULL) {
3108 			err = alloc_added_blob_tree_entry(&new_te, ct);
3109 			if (err)
3110 				goto done;
3111 			err = report_ct_status(ct, status_cb, status_arg);
3112 			if (err)
3113 				goto done;
3114 			ct->flags |= GOT_COMMITABLE_ADDED;
3115 			err = insert_tree_entry(new_te, &paths);
3116 			if (err)
3117 				goto done;
3118 		} else {
3119 			*slash = '\0'; /* trim trailing path components */
3120 			if (base_tree == NULL ||
3121 			    got_object_tree_find_entry(base_tree, child_path)
3122 			    == NULL) {
3123 				err = make_subtree_for_added_blob(&new_te,
3124 				    child_path, path_base_tree,
3125 				    commitable_paths, status_cb, status_arg,
3126 				    repo);
3127 				if (err)
3128 					goto done;
3129 				err = insert_tree_entry(new_te, &paths);
3130 				if (err)
3131 					goto done;
3132 			}
3133 		}
3134 	}
3135 
3136 	if (base_tree) {
3137 		/* Handle modified and deleted entries. */
3138 		base_entries = got_object_tree_get_entries(base_tree);
3139 		SIMPLEQ_FOREACH(te, &base_entries->head, entry) {
3140 			struct got_commitable *ct = NULL;
3141 
3142 			if (S_ISDIR(te->mode)) {
3143 				int modified;
3144 				err = got_object_tree_entry_dup(&new_te, te);
3145 				if (err)
3146 					goto done;
3147 				err = match_modified_subtree(&modified, te,
3148 				    path_base_tree, commitable_paths);
3149 				if (err)
3150 					goto done;
3151 				/* Avoid recursion into unmodified subtrees. */
3152 				if (modified) {
3153 					free(new_te->id);
3154 					err = write_subtree(&new_te->id, te,
3155 					    path_base_tree, commitable_paths,
3156 					    status_cb, status_arg, repo);
3157 					if (err)
3158 						goto done;
3159 				}
3160 				err = insert_tree_entry(new_te, &paths);
3161 				if (err)
3162 					goto done;
3163 				continue;
3164 			}
3165 
3166 			err = match_deleted_or_modified_ct(&ct, te,
3167 			    path_base_tree, commitable_paths);
3168 			if (ct) {
3169 				/* NB: Deleted entries get dropped here. */
3170 				if (ct->status == GOT_STATUS_MODIFY) {
3171 					err = alloc_modified_blob_tree_entry(
3172 					    &new_te, te, ct);
3173 					if (err)
3174 						goto done;
3175 					err = insert_tree_entry(new_te, &paths);
3176 					if (err)
3177 						goto done;
3178 				}
3179 				err = report_ct_status(ct, status_cb,
3180 				    status_arg);
3181 				if (err)
3182 					goto done;
3183 			} else {
3184 				/* Entry is unchanged; just copy it. */
3185 				err = got_object_tree_entry_dup(&new_te, te);
3186 				if (err)
3187 					goto done;
3188 				err = insert_tree_entry(new_te, &paths);
3189 				if (err)
3190 					goto done;
3191 			}
3192 		}
3193 	}
3194 
3195 	/* Write new list of entries; deleted entries have been dropped. */
3196 	TAILQ_FOREACH(pe, &paths, entry) {
3197 		struct got_tree_entry *te = pe->data;
3198 		new_tree_entries.nentries++;
3199 		SIMPLEQ_INSERT_TAIL(&new_tree_entries.head, te, entry);
3200 	}
3201 	err = got_object_tree_create(new_tree_id, &new_tree_entries, repo);
3202 done:
3203 	got_object_tree_entries_close(&new_tree_entries);
3204 	got_pathlist_free(&paths);
3205 	return err;
3206 }
3207 
3208 static const struct got_error *
3209 update_fileindex_after_commit(struct got_pathlist_head *commitable_paths,
3210     struct got_object_id *new_base_commit_id, struct got_fileindex *fileindex)
3211 {
3212 	const struct got_error *err = NULL;
3213 	struct got_pathlist_entry *pe;
3214 
3215 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3216 		struct got_fileindex_entry *ie;
3217 		struct got_commitable *ct = pe->data;
3218 
3219 		ie = got_fileindex_entry_get(fileindex, pe->path);
3220 		if (ie) {
3221 			if (ct->status == GOT_STATUS_DELETE) {
3222 				got_fileindex_entry_remove(fileindex, ie);
3223 				got_fileindex_entry_free(ie);
3224 			} else
3225 				err = got_fileindex_entry_update(ie,
3226 				    ct->ondisk_path, ct->blob_id->sha1,
3227 				    new_base_commit_id->sha1, 1);
3228 		} else {
3229 			err = got_fileindex_entry_alloc(&ie,
3230 			    ct->ondisk_path, pe->path, ct->blob_id->sha1,
3231 			    new_base_commit_id->sha1);
3232 			if (err)
3233 				break;
3234 			err = got_fileindex_entry_add(fileindex, ie);
3235 			if (err)
3236 				break;
3237 		}
3238 	}
3239 	return err;
3240 }
3241 
3242 static const struct got_error *
3243 check_ct_out_of_date(struct got_commitable *ct, struct got_repository *repo,
3244 	struct got_object_id *head_commit_id)
3245 {
3246 	const struct got_error *err = NULL;
3247 	struct got_object_id *id_in_head = NULL, *id = NULL;
3248 	struct got_commit_object *commit = NULL;
3249 	char *path = NULL;
3250 	const char *ct_path = ct->in_repo_path;
3251 
3252 	while (ct_path[0] == '/')
3253 		ct_path++;
3254 
3255 	/*
3256 	 * Ensure that no modifications were made to files *and their parents*
3257 	 * in commits between the file's base commit and the branch head.
3258 	 *
3259 	 * Checking the parents is important for detecting conflicting tree
3260 	 * configurations (files or parent folders might have been moved,
3261 	 * deleted, added again, etc.). Such changes need to be merged with
3262 	 * local changes before a commit can occur.
3263 	 *
3264 	 * The implication is that the file's (parent) entry in the root
3265 	 * directory must have the same ID in all relevant commits.
3266 	 */
3267 	if (ct->status != GOT_STATUS_ADD) {
3268 		struct got_object_qid *pid;
3269 		char *slash;
3270 		struct got_object_id *root_entry_id = NULL;
3271 
3272 		/* Trivial case: base commit == head commit */
3273 		if (got_object_id_cmp(ct->base_commit_id, head_commit_id) == 0)
3274 			return NULL;
3275 
3276 		/* Compute the path to the root directory's entry. */
3277 		path = strdup(ct_path);
3278 		if (path == NULL) {
3279 			err = got_error_from_errno("strdup");
3280 			goto done;
3281 		}
3282 		slash = strchr(path, '/');
3283 		if (slash)
3284 			*slash = '\0';
3285 
3286 		err = got_object_open_as_commit(&commit, repo, head_commit_id);
3287 		if (err)
3288 			goto done;
3289 
3290 		err = got_object_id_by_path(&root_entry_id, repo,
3291 		    head_commit_id, path);
3292 		if (err)
3293 			goto done;
3294 
3295 		pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(commit));
3296 		while (pid) {
3297 			struct got_commit_object *pcommit;
3298 
3299 			err = got_object_id_by_path(&id, repo, pid->id, path);
3300 			if (err) {
3301 				if (err->code != GOT_ERR_NO_TREE_ENTRY)
3302 					goto done;
3303 				err = NULL;
3304 				break;
3305 			}
3306 
3307 			err = got_object_id_by_path(&id, repo, pid->id, path);
3308 			if (err)
3309 				goto done;
3310 
3311 			if (got_object_id_cmp(id, root_entry_id) != 0) {
3312 				err = got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
3313 				break;
3314 			}
3315 
3316 			if (got_object_id_cmp(pid->id, ct->base_commit_id) == 0)
3317 				break; /* all relevant commits scanned */
3318 
3319 			err = got_object_open_as_commit(&pcommit, repo,
3320 			    pid->id);
3321 			if (err)
3322 				goto done;
3323 
3324 			got_object_commit_close(commit);
3325 			commit = pcommit;
3326 			pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(
3327 			    commit));
3328 		}
3329 	} else {
3330 		/* Require that added files don't exist in the branch head. */
3331 		err = got_object_id_by_path(&id_in_head, repo, head_commit_id,
3332 		    ct_path);
3333 		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
3334 			goto done;
3335 		err = id_in_head ? got_error(GOT_ERR_COMMIT_OUT_OF_DATE) : NULL;
3336 	}
3337 done:
3338 	if (commit)
3339 		got_object_commit_close(commit);
3340 	free(id_in_head);
3341 	free(id);
3342 	free(path);
3343 	return err;
3344 }
3345 
3346 const struct got_error *
3347 commit_worktree(struct got_object_id **new_commit_id,
3348     struct got_pathlist_head *commitable_paths,
3349     struct got_object_id *head_commit_id, struct got_worktree *worktree,
3350     const char *ondisk_path, const char *author, const char *committer,
3351     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3352     got_worktree_status_cb status_cb, void *status_arg,
3353     struct got_repository *repo)
3354 {
3355 	const struct got_error *err = NULL, *unlockerr = NULL;
3356 	struct got_pathlist_entry *pe;
3357 	const char *head_ref_name = NULL;
3358 	struct got_commit_object *head_commit = NULL;
3359 	struct got_reference *head_ref2 = NULL;
3360 	struct got_object_id *head_commit_id2 = NULL;
3361 	struct got_tree_object *head_tree = NULL;
3362 	struct got_object_id *new_tree_id = NULL;
3363 	struct got_object_id_queue parent_ids;
3364 	struct got_object_qid *pid = NULL;
3365 	char *logmsg = NULL;
3366 
3367 	*new_commit_id = NULL;
3368 
3369 	SIMPLEQ_INIT(&parent_ids);
3370 
3371 	err = got_object_open_as_commit(&head_commit, repo, head_commit_id);
3372 	if (err)
3373 		goto done;
3374 
3375 	err = got_object_open_as_tree(&head_tree, repo, head_commit->tree_id);
3376 	if (err)
3377 		goto done;
3378 
3379 	if (commit_msg_cb != NULL) {
3380 		err = commit_msg_cb(commitable_paths, &logmsg, commit_arg);
3381 		if (err)
3382 			goto done;
3383 	}
3384 
3385 	if (logmsg == NULL || strlen(logmsg) == 0) {
3386 		err = got_error(GOT_ERR_COMMIT_MSG_EMPTY);
3387 		goto done;
3388 	}
3389 
3390 	/* Create blobs from added and modified files and record their IDs. */
3391 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3392 		struct got_commitable *ct = pe->data;
3393 		char *ondisk_path;
3394 
3395 		if (ct->status != GOT_STATUS_ADD &&
3396 		    ct->status != GOT_STATUS_MODIFY)
3397 			continue;
3398 
3399 		if (asprintf(&ondisk_path, "%s/%s",
3400 		    worktree->root_path, pe->path) == -1) {
3401 			err = got_error_from_errno("asprintf");
3402 			goto done;
3403 		}
3404 		err = got_object_blob_create(&ct->blob_id, ondisk_path, repo);
3405 		free(ondisk_path);
3406 		if (err)
3407 			goto done;
3408 	}
3409 
3410 	/* Recursively write new tree objects. */
3411 	err = write_tree(&new_tree_id, head_tree, "/", commitable_paths,
3412 	    status_cb, status_arg, repo);
3413 	if (err)
3414 		goto done;
3415 
3416 	err = got_object_qid_alloc(&pid, worktree->base_commit_id);
3417 	if (err)
3418 		goto done;
3419 	SIMPLEQ_INSERT_TAIL(&parent_ids, pid, entry);
3420 	err = got_object_commit_create(new_commit_id, new_tree_id, &parent_ids,
3421 	    1, author, time(NULL), committer, time(NULL), logmsg, repo);
3422 	got_object_qid_free(pid);
3423 	if (logmsg != NULL)
3424 		free(logmsg);
3425 	if (err)
3426 		goto done;
3427 
3428 	/* Check if a concurrent commit to our branch has occurred. */
3429 	head_ref_name = got_worktree_get_head_ref_name(worktree);
3430 	if (head_ref_name == NULL) {
3431 		err = got_error_from_errno("got_worktree_get_head_ref_name");
3432 		goto done;
3433 	}
3434 	/* Lock the reference here to prevent concurrent modification. */
3435 	err = got_ref_open(&head_ref2, repo, head_ref_name, 1);
3436 	if (err)
3437 		goto done;
3438 	err = got_ref_resolve(&head_commit_id2, repo, head_ref2);
3439 	if (err)
3440 		goto done;
3441 	if (got_object_id_cmp(head_commit_id, head_commit_id2) != 0) {
3442 		err = got_error(GOT_ERR_COMMIT_HEAD_CHANGED);
3443 		goto done;
3444 	}
3445 	/* Update branch head in repository. */
3446 	err = got_ref_change_ref(head_ref2, *new_commit_id);
3447 	if (err)
3448 		goto done;
3449 	err = got_ref_write(head_ref2, repo);
3450 	if (err)
3451 		goto done;
3452 
3453 	err = got_worktree_set_base_commit_id(worktree, repo, *new_commit_id);
3454 	if (err)
3455 		goto done;
3456 
3457 	err = ref_base_commit(worktree, repo);
3458 	if (err)
3459 		goto done;
3460 done:
3461 	if (head_tree)
3462 		got_object_tree_close(head_tree);
3463 	if (head_commit)
3464 		got_object_commit_close(head_commit);
3465 	free(head_commit_id2);
3466 	if (head_ref2) {
3467 		unlockerr = got_ref_unlock(head_ref2);
3468 		if (unlockerr && err == NULL)
3469 			err = unlockerr;
3470 		got_ref_close(head_ref2);
3471 	}
3472 	return err;
3473 }
3474 
3475 const struct got_error *
3476 got_worktree_commit(struct got_object_id **new_commit_id,
3477     struct got_worktree *worktree, const char *ondisk_path,
3478     const char *author, const char *committer,
3479     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3480     got_worktree_status_cb status_cb, void *status_arg,
3481     struct got_repository *repo)
3482 {
3483 	const struct got_error *err = NULL, *unlockerr = NULL, *sync_err;
3484 	struct got_fileindex *fileindex = NULL;
3485 	char *fileindex_path = NULL, *relpath = NULL;
3486 	struct got_pathlist_head commitable_paths;
3487 	struct collect_commitables_arg cc_arg;
3488 	struct got_pathlist_entry *pe;
3489 	struct got_reference *head_ref = NULL;
3490 	struct got_object_id *head_commit_id = NULL;
3491 
3492 	*new_commit_id = NULL;
3493 
3494 	TAILQ_INIT(&commitable_paths);
3495 
3496 	err = lock_worktree(worktree, LOCK_EX);
3497 	if (err)
3498 		goto done;
3499 
3500 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3501 	if (err)
3502 		goto done;
3503 
3504 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3505 	if (err)
3506 		goto done;
3507 
3508 	if (ondisk_path) {
3509 		if (strcmp(ondisk_path, worktree->root_path) == 0) {
3510 			relpath = strdup("");
3511 			if (relpath == NULL) {
3512 				err = got_error_from_errno("strdup");
3513 				goto done;
3514 			}
3515 		} else {
3516 			err = got_path_skip_common_ancestor(&relpath,
3517 			    worktree->root_path, ondisk_path);
3518 			if (err)
3519 				return err;
3520 		}
3521 	}
3522 
3523 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3524 	if (err)
3525 		goto done;
3526 
3527 	cc_arg.commitable_paths = &commitable_paths;
3528 	cc_arg.worktree = worktree;
3529 	cc_arg.repo = repo;
3530 	err = worktree_status(worktree, relpath ? relpath : "",
3531 	    fileindex, repo, collect_commitables, &cc_arg, NULL, NULL);
3532 	if (err)
3533 		goto done;
3534 
3535 	if (TAILQ_EMPTY(&commitable_paths)) {
3536 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3537 		goto done;
3538 	}
3539 
3540 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3541 		struct got_commitable *ct = pe->data;
3542 		err = check_ct_out_of_date(ct, repo, head_commit_id);
3543 		if (err)
3544 			goto done;
3545 	}
3546 
3547 	err = commit_worktree(new_commit_id, &commitable_paths,
3548 	    head_commit_id, worktree, ondisk_path, author, committer,
3549 	    commit_msg_cb, commit_arg, status_cb, status_arg, repo);
3550 	if (err)
3551 		goto done;
3552 
3553 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
3554 	    fileindex);
3555 	sync_err = sync_fileindex(fileindex, fileindex_path);
3556 	if (sync_err && err == NULL)
3557 		err = sync_err;
3558 done:
3559 	if (fileindex)
3560 		got_fileindex_free(fileindex);
3561 	free(fileindex_path);
3562 	free(relpath);
3563 	unlockerr = lock_worktree(worktree, LOCK_SH);
3564 	if (unlockerr && err == NULL)
3565 		err = unlockerr;
3566 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3567 		struct got_commitable *ct = pe->data;
3568 		free_commitable(ct);
3569 	}
3570 	got_pathlist_free(&commitable_paths);
3571 	return err;
3572 }
3573 
3574 const char *
3575 got_commitable_get_path(struct got_commitable *ct)
3576 {
3577 	return ct->path;
3578 }
3579 
3580 unsigned int
3581 got_commitable_get_status(struct got_commitable *ct)
3582 {
3583 	return ct->status;
3584 }
3585 
3586 struct check_rebase_ok_arg {
3587 	struct got_worktree *worktree;
3588 	struct got_repository *repo;
3589 	int rebase_in_progress;
3590 };
3591 
3592 static const struct got_error *
3593 check_rebase_ok(void *arg, struct got_fileindex_entry *ie)
3594 {
3595 	const struct got_error *err = NULL;
3596 	struct check_rebase_ok_arg *a = arg;
3597 	unsigned char status;
3598 	struct stat sb;
3599 	char *ondisk_path;
3600 
3601 	if (!a->rebase_in_progress) {
3602 		/* Reject rebase of a work tree with mixed base commits. */
3603 		if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
3604 		    SHA1_DIGEST_LENGTH))
3605 			return got_error(GOT_ERR_MIXED_COMMITS);
3606 	}
3607 
3608 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
3609 	    == -1)
3610 		return got_error_from_errno("asprintf");
3611 
3612 	/* Reject rebase of a work tree with modified or conflicted files. */
3613 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
3614 	free(ondisk_path);
3615 	if (err)
3616 		return err;
3617 
3618 	if (a->rebase_in_progress) {
3619 		if (status == GOT_STATUS_CONFLICT)
3620 			return got_error(GOT_ERR_CONFLICTS);
3621 	} else if (status != GOT_STATUS_NO_CHANGE)
3622 		return got_error(GOT_ERR_MODIFIED);
3623 
3624 	return NULL;
3625 }
3626 
3627 const struct got_error *
3628 got_worktree_rebase_prepare(struct got_reference **new_base_branch_ref,
3629     struct got_reference **tmp_branch, struct got_fileindex **fileindex,
3630     struct got_worktree *worktree, struct got_reference *branch,
3631     struct got_repository *repo)
3632 {
3633 	const struct got_error *err = NULL;
3634 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
3635 	char *branch_ref_name = NULL;
3636 	char *fileindex_path = NULL;
3637 	struct check_rebase_ok_arg ok_arg;
3638 	struct got_reference *wt_branch = NULL, *branch_ref = NULL;
3639 
3640 	*new_base_branch_ref = NULL;
3641 	*tmp_branch = NULL;
3642 	*fileindex = NULL;
3643 
3644 	err = lock_worktree(worktree, LOCK_EX);
3645 	if (err)
3646 		return err;
3647 
3648 	err = open_fileindex(fileindex, &fileindex_path, worktree);
3649 	if (err)
3650 		goto done;
3651 
3652 	ok_arg.worktree = worktree;
3653 	ok_arg.repo = repo;
3654 	ok_arg.rebase_in_progress = 0;
3655 	err = got_fileindex_for_each_entry_safe(*fileindex, check_rebase_ok,
3656 	    &ok_arg);
3657 	if (err)
3658 		goto done;
3659 
3660 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3661 	if (err)
3662 		goto done;
3663 
3664 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3665 	if (err)
3666 		goto done;
3667 
3668 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3669 	if (err)
3670 		goto done;
3671 
3672 	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
3673 	    0);
3674 	if (err)
3675 		goto done;
3676 
3677 	err = got_ref_alloc_symref(new_base_branch_ref,
3678 	    new_base_branch_ref_name, wt_branch);
3679 	if (err)
3680 		goto done;
3681 	err = got_ref_write(*new_base_branch_ref, repo);
3682 	if (err)
3683 		goto done;
3684 
3685 	/* TODO Lock original branch's ref while rebasing? */
3686 
3687 	err = got_ref_alloc_symref(&branch_ref, branch_ref_name, branch);
3688 	if (err)
3689 		goto done;
3690 
3691 	err = got_ref_write(branch_ref, repo);
3692 	if (err)
3693 		goto done;
3694 
3695 	err = got_ref_alloc(tmp_branch, tmp_branch_name,
3696 	    worktree->base_commit_id);
3697 	if (err)
3698 		goto done;
3699 	err = got_ref_write(*tmp_branch, repo);
3700 	if (err)
3701 		goto done;
3702 
3703 	err = got_worktree_set_head_ref(worktree, *tmp_branch);
3704 	if (err)
3705 		goto done;
3706 done:
3707 	free(fileindex_path);
3708 	free(tmp_branch_name);
3709 	free(new_base_branch_ref_name);
3710 	free(branch_ref_name);
3711 	if (branch_ref)
3712 		got_ref_close(branch_ref);
3713 	if (wt_branch)
3714 		got_ref_close(wt_branch);
3715 	if (err) {
3716 		if (*new_base_branch_ref) {
3717 			got_ref_close(*new_base_branch_ref);
3718 			*new_base_branch_ref = NULL;
3719 		}
3720 		if (*tmp_branch) {
3721 			got_ref_close(*tmp_branch);
3722 			*tmp_branch = NULL;
3723 		}
3724 		if (*fileindex) {
3725 			got_fileindex_free(*fileindex);
3726 			*fileindex = NULL;
3727 		}
3728 		lock_worktree(worktree, LOCK_SH);
3729 	}
3730 	return err;
3731 }
3732 
3733 const struct got_error *
3734 got_worktree_rebase_continue(struct got_object_id **commit_id,
3735     struct got_reference **new_base_branch, struct got_reference **tmp_branch,
3736     struct got_reference **branch, struct got_fileindex **fileindex,
3737     struct got_worktree *worktree, struct got_repository *repo)
3738 {
3739 	const struct got_error *err;
3740 	char *commit_ref_name = NULL, *new_base_branch_ref_name = NULL;
3741 	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
3742 	struct got_reference *commit_ref = NULL, *branch_ref = NULL;
3743 	char *fileindex_path = NULL;
3744 
3745 	*commit_id = NULL;
3746 	*new_base_branch = NULL;
3747 	*tmp_branch = NULL;
3748 	*branch = NULL;
3749 	*fileindex = NULL;
3750 
3751 	err = lock_worktree(worktree, LOCK_EX);
3752 	if (err)
3753 		return err;
3754 
3755 	err = open_fileindex(fileindex, &fileindex_path, worktree);
3756 	if (err)
3757 		goto done;
3758 
3759 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3760 	if (err)
3761 		return err;
3762 
3763 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3764 	if (err)
3765 		goto done;
3766 
3767 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3768 	if (err)
3769 		goto done;
3770 
3771 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3772 	if (err)
3773 		goto done;
3774 
3775 	err = got_ref_open(&branch_ref, repo, branch_ref_name, 0);
3776 	if (err)
3777 		goto done;
3778 
3779 	err = got_ref_open(branch, repo,
3780 	    got_ref_get_symref_target(branch_ref), 0);
3781 	if (err)
3782 		goto done;
3783 
3784 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3785 	if (err)
3786 		goto done;
3787 
3788 	err = got_ref_resolve(commit_id, repo, commit_ref);
3789 	if (err)
3790 		goto done;
3791 
3792 	err = got_ref_open(new_base_branch, repo,
3793 	    new_base_branch_ref_name, 0);
3794 	if (err)
3795 		goto done;
3796 
3797 	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
3798 	if (err)
3799 		goto done;
3800 done:
3801 	free(commit_ref_name);
3802 	free(branch_ref_name);
3803 	free(fileindex_path);
3804 	if (commit_ref)
3805 		got_ref_close(commit_ref);
3806 	if (branch_ref)
3807 		got_ref_close(branch_ref);
3808 	if (err) {
3809 		free(*commit_id);
3810 		*commit_id = NULL;
3811 		if (*tmp_branch) {
3812 			got_ref_close(*tmp_branch);
3813 			*tmp_branch = NULL;
3814 		}
3815 		if (*new_base_branch) {
3816 			got_ref_close(*new_base_branch);
3817 			*new_base_branch = NULL;
3818 		}
3819 		if (*branch) {
3820 			got_ref_close(*branch);
3821 			*branch = NULL;
3822 		}
3823 		if (*fileindex) {
3824 			got_fileindex_free(*fileindex);
3825 			*fileindex = NULL;
3826 		}
3827 		lock_worktree(worktree, LOCK_SH);
3828 	}
3829 	return err;
3830 }
3831 
3832 const struct got_error *
3833 got_worktree_rebase_in_progress(int *in_progress, struct got_worktree *worktree)
3834 {
3835 	const struct got_error *err;
3836 	char *tmp_branch_name = NULL;
3837 
3838 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3839 	if (err)
3840 		return err;
3841 
3842 	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
3843 	free(tmp_branch_name);
3844 	return NULL;
3845 }
3846 
3847 static const struct got_error *
3848 collect_rebase_commit_msg(struct got_pathlist_head *commitable_paths,
3849     char **logmsg, void *arg)
3850 {
3851 	*logmsg = arg;
3852 	return NULL;
3853 }
3854 
3855 static const struct got_error *
3856 rebase_status(void *arg, unsigned char status, const char *path,
3857     struct got_object_id *blob_id, struct got_object_id *commit_id)
3858 {
3859 	return NULL;
3860 }
3861 
3862 struct collect_merged_paths_arg {
3863 	got_worktree_checkout_cb progress_cb;
3864 	void *progress_arg;
3865 	struct got_pathlist_head *merged_paths;
3866 };
3867 
3868 static const struct got_error *
3869 collect_merged_paths(void *arg, unsigned char status, const char *path)
3870 {
3871 	const struct got_error *err;
3872 	struct collect_merged_paths_arg *a = arg;
3873 	char *p;
3874 	struct got_pathlist_entry *new;
3875 
3876 	err = (*a->progress_cb)(a->progress_arg, status, path);
3877 	if (err)
3878 		return err;
3879 
3880 	if (status != GOT_STATUS_MERGE &&
3881 	    status != GOT_STATUS_ADD &&
3882 	    status != GOT_STATUS_DELETE &&
3883 	    status != GOT_STATUS_CONFLICT)
3884 		return NULL;
3885 
3886 	p = strdup(path);
3887 	if (p == NULL)
3888 		return got_error_from_errno("strdup");
3889 
3890 	err = got_pathlist_insert(&new, a->merged_paths, p, NULL);
3891 	if (err || new == NULL)
3892 		free(p);
3893 	return err;
3894 }
3895 
3896 void
3897 got_worktree_rebase_pathlist_free(struct got_pathlist_head *merged_paths)
3898 {
3899 	struct got_pathlist_entry *pe;
3900 
3901 	TAILQ_FOREACH(pe, merged_paths, entry)
3902 		free((char *)pe->path);
3903 
3904 	got_pathlist_free(merged_paths);
3905 }
3906 
3907 static const struct got_error *
3908 store_commit_id(const char *commit_ref_name, struct got_object_id *commit_id,
3909     struct got_repository *repo)
3910 {
3911 	const struct got_error *err;
3912 	struct got_reference *commit_ref = NULL;
3913 
3914 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3915 	if (err) {
3916 		if (err->code != GOT_ERR_NOT_REF)
3917 			goto done;
3918 		err = got_ref_alloc(&commit_ref, commit_ref_name, commit_id);
3919 		if (err)
3920 			goto done;
3921 		err = got_ref_write(commit_ref, repo);
3922 		if (err)
3923 			goto done;
3924 	} else {
3925 		struct got_object_id *stored_id;
3926 		int cmp;
3927 
3928 		err = got_ref_resolve(&stored_id, repo, commit_ref);
3929 		if (err)
3930 			goto done;
3931 		cmp = got_object_id_cmp(commit_id, stored_id);
3932 		free(stored_id);
3933 		if (cmp != 0) {
3934 			err = got_error(GOT_ERR_REBASE_COMMITID);
3935 			goto done;
3936 		}
3937 	}
3938 done:
3939 	if (commit_ref)
3940 		got_ref_close(commit_ref);
3941 	return err;
3942 }
3943 
3944 static const struct got_error *
3945 rebase_merge_files(struct got_pathlist_head *merged_paths,
3946     const char *commit_ref_name, struct got_worktree *worktree,
3947     struct got_fileindex *fileindex, struct got_object_id *parent_commit_id,
3948     struct got_object_id *commit_id, struct got_repository *repo,
3949     got_worktree_checkout_cb progress_cb, void *progress_arg,
3950     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
3951 {
3952 	const struct got_error *err;
3953 	struct got_reference *commit_ref = NULL;
3954 	struct collect_merged_paths_arg cmp_arg;
3955 	char *fileindex_path;
3956 
3957 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
3958 
3959 	err = get_fileindex_path(&fileindex_path, worktree);
3960 	if (err)
3961 		return err;
3962 
3963 	cmp_arg.progress_cb = progress_cb;
3964 	cmp_arg.progress_arg = progress_arg;
3965 	cmp_arg.merged_paths = merged_paths;
3966 	err = merge_files(worktree, fileindex, fileindex_path,
3967 	    parent_commit_id, commit_id, repo, collect_merged_paths,
3968 	    &cmp_arg, cancel_cb, cancel_arg);
3969 	if (commit_ref)
3970 		got_ref_close(commit_ref);
3971 	return err;
3972 }
3973 
3974 const struct got_error *
3975 got_worktree_rebase_merge_files(struct got_pathlist_head *merged_paths,
3976     struct got_worktree *worktree, struct got_fileindex *fileindex,
3977     struct got_object_id *parent_commit_id, struct got_object_id *commit_id,
3978     struct got_repository *repo,
3979     got_worktree_checkout_cb progress_cb, void *progress_arg,
3980     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
3981 {
3982 	const struct got_error *err;
3983 	char *commit_ref_name;
3984 
3985 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3986 	if (err)
3987 		return err;
3988 
3989 	err = store_commit_id(commit_ref_name, commit_id, repo);
3990 	if (err)
3991 		goto done;
3992 
3993 	err = rebase_merge_files(merged_paths, commit_ref_name, worktree,
3994 	    fileindex, parent_commit_id, commit_id, repo, progress_cb,
3995 	    progress_arg, cancel_cb, cancel_arg);
3996 done:
3997 	free(commit_ref_name);
3998 	return err;
3999 }
4000 
4001 const struct got_error *
4002 got_worktree_histedit_merge_files(struct got_pathlist_head *merged_paths,
4003     struct got_worktree *worktree, struct got_fileindex *fileindex,
4004     struct got_object_id *parent_commit_id, struct got_object_id *commit_id,
4005     struct got_repository *repo,
4006     got_worktree_checkout_cb progress_cb, void *progress_arg,
4007     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
4008 {
4009 	const struct got_error *err;
4010 	char *commit_ref_name;
4011 
4012 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4013 	if (err)
4014 		return err;
4015 
4016 	err = store_commit_id(commit_ref_name, commit_id, repo);
4017 	if (err)
4018 		goto done;
4019 
4020 	err = rebase_merge_files(merged_paths, commit_ref_name, worktree,
4021 	    fileindex, parent_commit_id, commit_id, repo, progress_cb,
4022 	    progress_arg, cancel_cb, cancel_arg);
4023 done:
4024 	free(commit_ref_name);
4025 	return err;
4026 }
4027 
4028 static const struct got_error *
4029 rebase_commit(struct got_object_id **new_commit_id,
4030     struct got_pathlist_head *merged_paths, struct got_reference *commit_ref,
4031     struct got_worktree *worktree, struct got_fileindex *fileindex,
4032     struct got_reference *tmp_branch, struct got_commit_object *orig_commit,
4033     const char *new_logmsg, struct got_repository *repo)
4034 {
4035 	const struct got_error *err, *sync_err;
4036 	struct got_pathlist_head commitable_paths;
4037 	struct collect_commitables_arg cc_arg;
4038 	char *fileindex_path = NULL;
4039 	struct got_reference *head_ref = NULL;
4040 	struct got_object_id *head_commit_id = NULL;
4041 	char *logmsg = NULL;
4042 
4043 	TAILQ_INIT(&commitable_paths);
4044 	*new_commit_id = NULL;
4045 
4046 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
4047 
4048 	err = get_fileindex_path(&fileindex_path, worktree);
4049 	if (err)
4050 		return err;
4051 
4052 	cc_arg.commitable_paths = &commitable_paths;
4053 	cc_arg.worktree = worktree;
4054 	cc_arg.repo = repo;
4055 	/*
4056 	 * If possible get the status of individual files directly to
4057 	 * avoid crawling the entire work tree once per rebased commit.
4058 	 * TODO: Ideally, merged_paths would contain a list of commitables
4059 	 * we could use so we could skip worktree_status() entirely.
4060 	 */
4061 	if (merged_paths) {
4062 		struct got_pathlist_entry *pe;
4063 		if (TAILQ_EMPTY(merged_paths)) {
4064 			err = got_error(GOT_ERR_NO_MERGED_PATHS);
4065 			goto done;
4066 		}
4067 		TAILQ_FOREACH(pe, merged_paths, entry) {
4068 			err = worktree_status(worktree, pe->path, fileindex,
4069 			    repo, collect_commitables, &cc_arg, NULL, NULL);
4070 			if (err)
4071 				goto done;
4072 		}
4073 	} else {
4074 		err = worktree_status(worktree, "", fileindex, repo,
4075 		    collect_commitables, &cc_arg, NULL, NULL);
4076 		if (err)
4077 			goto done;
4078 	}
4079 
4080 	if (TAILQ_EMPTY(&commitable_paths)) {
4081 		/* No-op change; commit will be elided. */
4082 		err = got_ref_delete(commit_ref, repo);
4083 		if (err)
4084 			goto done;
4085 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
4086 		goto done;
4087 	}
4088 
4089 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
4090 	if (err)
4091 		goto done;
4092 
4093 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
4094 	if (err)
4095 		goto done;
4096 
4097 	if (new_logmsg)
4098 		logmsg = strdup(new_logmsg);
4099 	else
4100 		logmsg = strdup(got_object_commit_get_logmsg(orig_commit));
4101 	if (logmsg == NULL)
4102 		return got_error_from_errno("strdup");
4103 
4104 	err = commit_worktree(new_commit_id, &commitable_paths, head_commit_id,
4105 	    worktree, NULL, got_object_commit_get_author(orig_commit),
4106 	    got_object_commit_get_committer(orig_commit),
4107 	    collect_rebase_commit_msg, logmsg, rebase_status, NULL, repo);
4108 	if (err)
4109 		goto done;
4110 
4111 	err = got_ref_change_ref(tmp_branch, *new_commit_id);
4112 	if (err)
4113 		goto done;
4114 
4115 	err = got_ref_delete(commit_ref, repo);
4116 	if (err)
4117 		goto done;
4118 
4119 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
4120 	    fileindex);
4121 	sync_err = sync_fileindex(fileindex, fileindex_path);
4122 	if (sync_err && err == NULL)
4123 		err = sync_err;
4124 done:
4125 	free(fileindex_path);
4126 	free(head_commit_id);
4127 	if (head_ref)
4128 		got_ref_close(head_ref);
4129 	if (err) {
4130 		free(*new_commit_id);
4131 		*new_commit_id = NULL;
4132 	}
4133 	return err;
4134 }
4135 
4136 const struct got_error *
4137 got_worktree_rebase_commit(struct got_object_id **new_commit_id,
4138     struct got_pathlist_head *merged_paths, struct got_worktree *worktree,
4139     struct got_fileindex *fileindex, struct got_reference *tmp_branch,
4140     struct got_commit_object *orig_commit,
4141     struct got_object_id *orig_commit_id, struct got_repository *repo)
4142 {
4143 	const struct got_error *err;
4144 	char *commit_ref_name;
4145 	struct got_reference *commit_ref = NULL;
4146 	struct got_object_id *commit_id = NULL;
4147 
4148 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4149 	if (err)
4150 		return err;
4151 
4152 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
4153 	if (err)
4154 		goto done;
4155 	err = got_ref_resolve(&commit_id, repo, commit_ref);
4156 	if (err)
4157 		goto done;
4158 	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
4159 		err = got_error(GOT_ERR_REBASE_COMMITID);
4160 		goto done;
4161 	}
4162 
4163 	err = rebase_commit(new_commit_id, merged_paths, commit_ref,
4164 	    worktree, fileindex, tmp_branch, orig_commit, NULL, repo);
4165 done:
4166 	if (commit_ref)
4167 		got_ref_close(commit_ref);
4168 	free(commit_ref_name);
4169 	free(commit_id);
4170 	return err;
4171 }
4172 
4173 const struct got_error *
4174 got_worktree_histedit_commit(struct got_object_id **new_commit_id,
4175     struct got_pathlist_head *merged_paths, struct got_worktree *worktree,
4176     struct got_fileindex *fileindex, struct got_reference *tmp_branch,
4177     struct got_commit_object *orig_commit,
4178     struct got_object_id *orig_commit_id, const char *new_logmsg,
4179     struct got_repository *repo)
4180 {
4181 	const struct got_error *err;
4182 	char *commit_ref_name;
4183 	struct got_reference *commit_ref = NULL;
4184 	struct got_object_id *commit_id = NULL;
4185 
4186 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4187 	if (err)
4188 		return err;
4189 
4190 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
4191 	if (err)
4192 		goto done;
4193 	err = got_ref_resolve(&commit_id, repo, commit_ref);
4194 	if (err)
4195 		goto done;
4196 	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
4197 		err = got_error(GOT_ERR_HISTEDIT_COMMITID);
4198 		goto done;
4199 	}
4200 
4201 	err = rebase_commit(new_commit_id, merged_paths, commit_ref,
4202 	    worktree, fileindex, tmp_branch, orig_commit, new_logmsg, repo);
4203 done:
4204 	if (commit_ref)
4205 		got_ref_close(commit_ref);
4206 	free(commit_ref_name);
4207 	free(commit_id);
4208 	return err;
4209 }
4210 
4211 const struct got_error *
4212 got_worktree_rebase_postpone(struct got_worktree *worktree,
4213     struct got_fileindex *fileindex)
4214 {
4215 	if (fileindex)
4216 		got_fileindex_free(fileindex);
4217 	return lock_worktree(worktree, LOCK_SH);
4218 }
4219 
4220 static const struct got_error *
4221 delete_ref(const char *name, struct got_repository *repo)
4222 {
4223 	const struct got_error *err;
4224 	struct got_reference *ref;
4225 
4226 	err = got_ref_open(&ref, repo, name, 0);
4227 	if (err) {
4228 		if (err->code == GOT_ERR_NOT_REF)
4229 			return NULL;
4230 		return err;
4231 	}
4232 
4233 	err = got_ref_delete(ref, repo);
4234 	got_ref_close(ref);
4235 	return err;
4236 }
4237 
4238 static const struct got_error *
4239 delete_rebase_refs(struct got_worktree *worktree, struct got_repository *repo)
4240 {
4241 	const struct got_error *err;
4242 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
4243 	char *branch_ref_name = NULL, *commit_ref_name = NULL;
4244 
4245 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
4246 	if (err)
4247 		goto done;
4248 	err = delete_ref(tmp_branch_name, repo);
4249 	if (err)
4250 		goto done;
4251 
4252 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
4253 	if (err)
4254 		goto done;
4255 	err = delete_ref(new_base_branch_ref_name, repo);
4256 	if (err)
4257 		goto done;
4258 
4259 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
4260 	if (err)
4261 		goto done;
4262 	err = delete_ref(branch_ref_name, repo);
4263 	if (err)
4264 		goto done;
4265 
4266 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4267 	if (err)
4268 		goto done;
4269 	err = delete_ref(commit_ref_name, repo);
4270 	if (err)
4271 		goto done;
4272 
4273 done:
4274 	free(tmp_branch_name);
4275 	free(new_base_branch_ref_name);
4276 	free(branch_ref_name);
4277 	free(commit_ref_name);
4278 	return err;
4279 }
4280 
4281 const struct got_error *
4282 got_worktree_rebase_complete(struct got_worktree *worktree,
4283     struct got_fileindex *fileindex, struct got_reference *new_base_branch,
4284     struct got_reference *tmp_branch, struct got_reference *rebased_branch,
4285     struct got_repository *repo)
4286 {
4287 	const struct got_error *err, *unlockerr;
4288 	struct got_object_id *new_head_commit_id = NULL;
4289 
4290 	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
4291 	if (err)
4292 		return err;
4293 
4294 	err = got_ref_change_ref(rebased_branch, new_head_commit_id);
4295 	if (err)
4296 		goto done;
4297 
4298 	err = got_ref_write(rebased_branch, repo);
4299 	if (err)
4300 		goto done;
4301 
4302 	err = got_worktree_set_head_ref(worktree, rebased_branch);
4303 	if (err)
4304 		goto done;
4305 
4306 	err = delete_rebase_refs(worktree, repo);
4307 done:
4308 	if (fileindex)
4309 		got_fileindex_free(fileindex);
4310 	free(new_head_commit_id);
4311 	unlockerr = lock_worktree(worktree, LOCK_SH);
4312 	if (unlockerr && err == NULL)
4313 		err = unlockerr;
4314 	return err;
4315 }
4316 
4317 struct collect_revertible_paths_arg {
4318 	struct got_pathlist_head *revertible_paths;
4319 	struct got_worktree *worktree;
4320 };
4321 
4322 static const struct got_error *
4323 collect_revertible_paths(void *arg, unsigned char status, const char *relpath,
4324     struct got_object_id *blob_id, struct got_object_id *commit_id)
4325 {
4326 	struct collect_revertible_paths_arg *a = arg;
4327 	const struct got_error *err = NULL;
4328 	struct got_pathlist_entry *new = NULL;
4329 	char *path = NULL;
4330 
4331 	if (status != GOT_STATUS_ADD &&
4332 	    status != GOT_STATUS_DELETE &&
4333 	    status != GOT_STATUS_MODIFY &&
4334 	    status != GOT_STATUS_CONFLICT &&
4335 	    status != GOT_STATUS_MISSING)
4336 		return NULL;
4337 
4338 	if (asprintf(&path, "%s/%s", a->worktree->root_path, relpath) == -1)
4339 		return got_error_from_errno("asprintf");
4340 
4341 	err = got_pathlist_insert(&new, a->revertible_paths, path, NULL);
4342 	if (err || new == NULL)
4343 		free(path);
4344 	return err;
4345 }
4346 
4347 const struct got_error *
4348 got_worktree_rebase_abort(struct got_worktree *worktree,
4349     struct got_fileindex *fileindex, struct got_repository *repo,
4350     struct got_reference *new_base_branch,
4351      got_worktree_checkout_cb progress_cb, void *progress_arg)
4352 {
4353 	const struct got_error *err, *unlockerr, *sync_err;
4354 	struct got_reference *resolved = NULL;
4355 	struct got_object_id *commit_id = NULL;
4356 	char *fileindex_path = NULL;
4357 	struct got_pathlist_head revertible_paths;
4358 	struct got_pathlist_entry *pe;
4359 	struct collect_revertible_paths_arg crp_arg;
4360 	struct got_object_id *tree_id = NULL;
4361 
4362 	TAILQ_INIT(&revertible_paths);
4363 
4364 	err = lock_worktree(worktree, LOCK_EX);
4365 	if (err)
4366 		return err;
4367 
4368 	err = got_ref_open(&resolved, repo,
4369 	    got_ref_get_symref_target(new_base_branch), 0);
4370 	if (err)
4371 		goto done;
4372 
4373 	err = got_worktree_set_head_ref(worktree, resolved);
4374 	if (err)
4375 		goto done;
4376 
4377 	/*
4378 	 * XXX commits to the base branch could have happened while
4379 	 * we were busy rebasing; should we store the original commit ID
4380 	 * when rebase begins and read it back here?
4381 	 */
4382 	err = got_ref_resolve(&commit_id, repo, resolved);
4383 	if (err)
4384 		goto done;
4385 
4386 	err = got_worktree_set_base_commit_id(worktree, repo, commit_id);
4387 	if (err)
4388 		goto done;
4389 
4390 	err = got_object_id_by_path(&tree_id, repo,
4391 	    worktree->base_commit_id, worktree->path_prefix);
4392 	if (err)
4393 		goto done;
4394 
4395 	err = delete_rebase_refs(worktree, repo);
4396 	if (err)
4397 		goto done;
4398 
4399 	err = get_fileindex_path(&fileindex_path, worktree);
4400 	if (err)
4401 		goto done;
4402 
4403 	crp_arg.revertible_paths = &revertible_paths;
4404 	crp_arg.worktree = worktree;
4405 	err = worktree_status(worktree, "", fileindex, repo,
4406 	    collect_revertible_paths, &crp_arg, NULL, NULL);
4407 	if (err)
4408 		goto done;
4409 
4410 	TAILQ_FOREACH(pe, &revertible_paths, entry) {
4411 		err = revert_file(worktree, fileindex, pe->path,
4412 		    progress_cb, progress_arg, repo);
4413 		if (err)
4414 			goto sync;
4415 	}
4416 
4417 	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
4418 	    repo, progress_cb, progress_arg, NULL, NULL);
4419 sync:
4420 	sync_err = sync_fileindex(fileindex, fileindex_path);
4421 	if (sync_err && err == NULL)
4422 		err = sync_err;
4423 done:
4424 	got_ref_close(resolved);
4425 	free(tree_id);
4426 	free(commit_id);
4427 	if (fileindex)
4428 		got_fileindex_free(fileindex);
4429 	free(fileindex_path);
4430 	TAILQ_FOREACH(pe, &revertible_paths, entry)
4431 		free((char *)pe->path);
4432 	got_pathlist_free(&revertible_paths);
4433 
4434 	unlockerr = lock_worktree(worktree, LOCK_SH);
4435 	if (unlockerr && err == NULL)
4436 		err = unlockerr;
4437 	return err;
4438 }
4439 
4440 const struct got_error *
4441 got_worktree_histedit_prepare(struct got_reference **tmp_branch,
4442     struct got_reference **branch_ref, struct got_object_id **base_commit_id,
4443     struct got_fileindex **fileindex, struct got_worktree *worktree,
4444     struct got_repository *repo)
4445 {
4446 	const struct got_error *err = NULL;
4447 	char *tmp_branch_name = NULL;
4448 	char *branch_ref_name = NULL;
4449 	char *base_commit_ref_name = NULL;
4450 	char *fileindex_path = NULL;
4451 	struct check_rebase_ok_arg ok_arg;
4452 	struct got_reference *wt_branch = NULL;
4453 	struct got_reference *base_commit_ref = NULL;
4454 
4455 	*tmp_branch = NULL;
4456 	*branch_ref = NULL;
4457 	*base_commit_id = NULL;
4458 	*fileindex = NULL;
4459 
4460 	err = lock_worktree(worktree, LOCK_EX);
4461 	if (err)
4462 		return err;
4463 
4464 	err = open_fileindex(fileindex, &fileindex_path, worktree);
4465 	if (err)
4466 		goto done;
4467 
4468 	ok_arg.worktree = worktree;
4469 	ok_arg.repo = repo;
4470 	ok_arg.rebase_in_progress = 0;
4471 	err = got_fileindex_for_each_entry_safe(*fileindex, check_rebase_ok,
4472 	    &ok_arg);
4473 	if (err)
4474 		goto done;
4475 
4476 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4477 	if (err)
4478 		goto done;
4479 
4480 	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
4481 	if (err)
4482 		goto done;
4483 
4484 	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
4485 	    worktree);
4486 	if (err)
4487 		goto done;
4488 
4489 	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
4490 	    0);
4491 	if (err)
4492 		goto done;
4493 
4494 	err = got_ref_alloc_symref(branch_ref, branch_ref_name, wt_branch);
4495 	if (err)
4496 		goto done;
4497 
4498 	err = got_ref_write(*branch_ref, repo);
4499 	if (err)
4500 		goto done;
4501 
4502 	err = got_ref_alloc(&base_commit_ref, base_commit_ref_name,
4503 	    worktree->base_commit_id);
4504 	if (err)
4505 		goto done;
4506 	err = got_ref_write(base_commit_ref, repo);
4507 	if (err)
4508 		goto done;
4509 	*base_commit_id = got_object_id_dup(worktree->base_commit_id);
4510 	if (*base_commit_id == NULL) {
4511 		err = got_error_from_errno("got_object_id_dup");
4512 		goto done;
4513 	}
4514 
4515 	err = got_ref_alloc(tmp_branch, tmp_branch_name,
4516 	    worktree->base_commit_id);
4517 	if (err)
4518 		goto done;
4519 	err = got_ref_write(*tmp_branch, repo);
4520 	if (err)
4521 		goto done;
4522 
4523 	err = got_worktree_set_head_ref(worktree, *tmp_branch);
4524 	if (err)
4525 		goto done;
4526 done:
4527 	free(fileindex_path);
4528 	free(tmp_branch_name);
4529 	free(branch_ref_name);
4530 	free(base_commit_ref_name);
4531 	if (wt_branch)
4532 		got_ref_close(wt_branch);
4533 	if (err) {
4534 		if (*branch_ref) {
4535 			got_ref_close(*branch_ref);
4536 			*branch_ref = NULL;
4537 		}
4538 		if (*tmp_branch) {
4539 			got_ref_close(*tmp_branch);
4540 			*tmp_branch = NULL;
4541 		}
4542 		free(*base_commit_id);
4543 		if (*fileindex) {
4544 			got_fileindex_free(*fileindex);
4545 			*fileindex = NULL;
4546 		}
4547 		lock_worktree(worktree, LOCK_SH);
4548 	}
4549 	return err;
4550 }
4551 
4552 const struct got_error *
4553 got_worktree_histedit_postpone(struct got_worktree *worktree,
4554     struct got_fileindex *fileindex)
4555 {
4556 	if (fileindex)
4557 		got_fileindex_free(fileindex);
4558 	return lock_worktree(worktree, LOCK_SH);
4559 }
4560 
4561 const struct got_error *
4562 got_worktree_histedit_in_progress(int *in_progress,
4563     struct got_worktree *worktree)
4564 {
4565 	const struct got_error *err;
4566 	char *tmp_branch_name = NULL;
4567 
4568 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4569 	if (err)
4570 		return err;
4571 
4572 	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
4573 	free(tmp_branch_name);
4574 	return NULL;
4575 }
4576 
4577 const struct got_error *
4578 got_worktree_histedit_continue(struct got_object_id **commit_id,
4579     struct got_reference **tmp_branch, struct got_reference **branch_ref,
4580     struct got_object_id **base_commit_id, struct got_fileindex **fileindex,
4581     struct got_worktree *worktree, struct got_repository *repo)
4582 {
4583 	const struct got_error *err;
4584 	char *commit_ref_name = NULL, *base_commit_ref_name = NULL;
4585 	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
4586 	struct got_reference *commit_ref = NULL;
4587 	struct got_reference *base_commit_ref = NULL;
4588 	char *fileindex_path = NULL;
4589 
4590 	*commit_id = NULL;
4591 	*tmp_branch = NULL;
4592 	*base_commit_id = NULL;
4593 	*fileindex = NULL;
4594 
4595 	err = lock_worktree(worktree, LOCK_EX);
4596 	if (err)
4597 		return err;
4598 
4599 	err = open_fileindex(fileindex, &fileindex_path, worktree);
4600 	if (err)
4601 		goto done;
4602 
4603 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4604 	if (err)
4605 		return err;
4606 
4607 	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
4608 	if (err)
4609 		goto done;
4610 
4611 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4612 	if (err)
4613 		goto done;
4614 
4615 	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
4616 	    worktree);
4617 	if (err)
4618 		goto done;
4619 
4620 	err = got_ref_open(branch_ref, repo, branch_ref_name, 0);
4621 	if (err)
4622 		goto done;
4623 
4624 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
4625 	if (err)
4626 		goto done;
4627 	err = got_ref_resolve(commit_id, repo, commit_ref);
4628 	if (err)
4629 		goto done;
4630 
4631 	err = got_ref_open(&base_commit_ref, repo, base_commit_ref_name, 0);
4632 	if (err)
4633 		goto done;
4634 	err = got_ref_resolve(base_commit_id, repo, base_commit_ref);
4635 	if (err)
4636 		goto done;
4637 
4638 	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
4639 	if (err)
4640 		goto done;
4641 done:
4642 	free(commit_ref_name);
4643 	free(branch_ref_name);
4644 	free(fileindex_path);
4645 	if (commit_ref)
4646 		got_ref_close(commit_ref);
4647 	if (base_commit_ref)
4648 		got_ref_close(base_commit_ref);
4649 	if (err) {
4650 		free(*commit_id);
4651 		*commit_id = NULL;
4652 		free(*base_commit_id);
4653 		*base_commit_id = NULL;
4654 		if (*tmp_branch) {
4655 			got_ref_close(*tmp_branch);
4656 			*tmp_branch = NULL;
4657 		}
4658 		if (*fileindex) {
4659 			got_fileindex_free(*fileindex);
4660 			*fileindex = NULL;
4661 		}
4662 		lock_worktree(worktree, LOCK_EX);
4663 	}
4664 	return err;
4665 }
4666 
4667 static const struct got_error *
4668 delete_histedit_refs(struct got_worktree *worktree, struct got_repository *repo)
4669 {
4670 	const struct got_error *err;
4671 	char *tmp_branch_name = NULL, *base_commit_ref_name = NULL;
4672 	char *branch_ref_name = NULL, *commit_ref_name = NULL;
4673 
4674 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4675 	if (err)
4676 		goto done;
4677 	err = delete_ref(tmp_branch_name, repo);
4678 	if (err)
4679 		goto done;
4680 
4681 	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
4682 	    worktree);
4683 	if (err)
4684 		goto done;
4685 	err = delete_ref(base_commit_ref_name, repo);
4686 	if (err)
4687 		goto done;
4688 
4689 	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
4690 	if (err)
4691 		goto done;
4692 	err = delete_ref(branch_ref_name, repo);
4693 	if (err)
4694 		goto done;
4695 
4696 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4697 	if (err)
4698 		goto done;
4699 	err = delete_ref(commit_ref_name, repo);
4700 	if (err)
4701 		goto done;
4702 done:
4703 	free(tmp_branch_name);
4704 	free(base_commit_ref_name);
4705 	free(branch_ref_name);
4706 	free(commit_ref_name);
4707 	return err;
4708 }
4709 
4710 const struct got_error *
4711 got_worktree_histedit_abort(struct got_worktree *worktree,
4712     struct got_fileindex *fileindex, struct got_repository *repo,
4713     struct got_reference *branch, struct got_object_id *base_commit_id,
4714     got_worktree_checkout_cb progress_cb, void *progress_arg)
4715 {
4716 	const struct got_error *err, *unlockerr, *sync_err;
4717 	struct got_reference *resolved = NULL;
4718 	char *fileindex_path = NULL;
4719 	struct got_pathlist_head revertible_paths;
4720 	struct got_pathlist_entry *pe;
4721 	struct collect_revertible_paths_arg crp_arg;
4722 	struct got_object_id *tree_id = NULL;
4723 
4724 	TAILQ_INIT(&revertible_paths);
4725 
4726 	err = lock_worktree(worktree, LOCK_EX);
4727 	if (err)
4728 		return err;
4729 
4730 	err = got_ref_open(&resolved, repo,
4731 	    got_ref_get_symref_target(branch), 0);
4732 	if (err)
4733 		goto done;
4734 
4735 	err = got_worktree_set_head_ref(worktree, resolved);
4736 	if (err)
4737 		goto done;
4738 
4739 	err = got_worktree_set_base_commit_id(worktree, repo, base_commit_id);
4740 	if (err)
4741 		goto done;
4742 
4743 	err = got_object_id_by_path(&tree_id, repo, base_commit_id,
4744 	    worktree->path_prefix);
4745 	if (err)
4746 		goto done;
4747 
4748 	err = delete_histedit_refs(worktree, repo);
4749 	if (err)
4750 		goto done;
4751 
4752 	err = get_fileindex_path(&fileindex_path, worktree);
4753 	if (err)
4754 		goto done;
4755 
4756 	crp_arg.revertible_paths = &revertible_paths;
4757 	crp_arg.worktree = worktree;
4758 	err = worktree_status(worktree, "", fileindex, repo,
4759 	    collect_revertible_paths, &crp_arg, NULL, NULL);
4760 	if (err)
4761 		goto done;
4762 
4763 	TAILQ_FOREACH(pe, &revertible_paths, entry) {
4764 		err = revert_file(worktree, fileindex, pe->path,
4765 		    progress_cb, progress_arg, repo);
4766 		if (err)
4767 			goto sync;
4768 	}
4769 
4770 	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
4771 	    repo, progress_cb, progress_arg, NULL, NULL);
4772 sync:
4773 	sync_err = sync_fileindex(fileindex, fileindex_path);
4774 	if (sync_err && err == NULL)
4775 		err = sync_err;
4776 done:
4777 	got_ref_close(resolved);
4778 	free(tree_id);
4779 	free(fileindex_path);
4780 	TAILQ_FOREACH(pe, &revertible_paths, entry)
4781 		free((char *)pe->path);
4782 	got_pathlist_free(&revertible_paths);
4783 
4784 	unlockerr = lock_worktree(worktree, LOCK_SH);
4785 	if (unlockerr && err == NULL)
4786 		err = unlockerr;
4787 	return err;
4788 }
4789 
4790 const struct got_error *
4791 got_worktree_histedit_complete(struct got_worktree *worktree,
4792     struct got_fileindex *fileindex, struct got_reference *tmp_branch,
4793     struct got_reference *edited_branch, struct got_repository *repo)
4794 {
4795 	const struct got_error *err, *unlockerr;
4796 	struct got_object_id *new_head_commit_id = NULL;
4797 	struct got_reference *resolved = NULL;
4798 
4799 	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
4800 	if (err)
4801 		return err;
4802 
4803 	err = got_ref_open(&resolved, repo,
4804 	    got_ref_get_symref_target(edited_branch), 0);
4805 	if (err)
4806 		goto done;
4807 
4808 	err = got_ref_change_ref(resolved, new_head_commit_id);
4809 	if (err)
4810 		goto done;
4811 
4812 	err = got_ref_write(resolved, repo);
4813 	if (err)
4814 		goto done;
4815 
4816 	err = got_worktree_set_head_ref(worktree, resolved);
4817 	if (err)
4818 		goto done;
4819 
4820 	err = delete_histedit_refs(worktree, repo);
4821 done:
4822 	if (fileindex)
4823 		got_fileindex_free(fileindex);
4824 	free(new_head_commit_id);
4825 	unlockerr = lock_worktree(worktree, LOCK_SH);
4826 	if (unlockerr && err == NULL)
4827 		err = unlockerr;
4828 	return err;
4829 }
4830 
4831 const struct got_error *
4832 got_worktree_histedit_skip_commit(struct got_worktree *worktree,
4833     struct got_object_id *commit_id, struct got_repository *repo)
4834 {
4835 	const struct got_error *err;
4836 	char *commit_ref_name;
4837 
4838 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4839 	if (err)
4840 		return err;
4841 
4842 	err = store_commit_id(commit_ref_name, commit_id, repo);
4843 	if (err)
4844 		goto done;
4845 
4846 	err = delete_ref(commit_ref_name, repo);
4847 done:
4848 	free(commit_ref_name);
4849 	return err;
4850 }